I also believe I'm qualified to speak on this issue as I was very worried about this from a very early time (even bought masks in late January). Others have brought up some good points here but I would say that the key issue you had is failure to pay attention to details. It may be true that the news likes to cause unnecessary hype over things for attention, but it is the details of the situation that really set this one apart from others.

1. After acknowledging human to human transmission, early reports suggested that the virus was capable of spreading through respiratory routes without the host displaying any symptoms of illness. This is an extremely distinct and alarming feature and is the main reason I started flipping out.
2. You may not have had ready access to this information, but people on Chinese social media were posting videos of packed hospitals in Wuhan. A back of the envelope estimation of the scale of the pandemic using estimates of hospital capacity in the region meant that the epidemic was far larger than reported at the time.
3. At some point in February we found several cases of COVID in the United States that could not be traced to any other known case of COVID. Again, if you pay attention to the details and implications this means more than if you just read the headline passively.

When China quarantines an entire city, you should be afraid of what's in that city.

I think I'm qualified to answer this question because I was paying attention to COVID-19 since the Wuhan quarantine, many months before the pandemic spread to the West. The day person-to-person spread was confirmed in the United States, I sprung into action.

You made two mistakes.

• You treated the news as something other than a propaganda machine. News is more noise than signal. We have known the world is at risk of a deadly pandemic for many years, yet the news dramatically underestimated the importance of COVID in the first several months of the pandemic.
• You didn't grok that pandemics grow exponentially and have long-tailed outcomes.

Our ancestors must rarely have encountered cases of exponential growth, because our intuitions are no guide here

―Startup = Growth by Paul Graham

Here are the antidotes.

• Ignore the news. Focus on long-term knowledge instead.
• Create personal fire alarms for events with the potential for sustained exponential growth. More generally, you should prepare far in advance to protect yourself from anything the authorities are unprepared for (especially disasters unprecedented in living memory).

It's quite possible that you didn't make a mistake. There are a few hints at mistakes in the post, but that's presumably just a very short approximation of your actual reasoning.

I'd consider it problematic to treat degree of media panic as a decent proxy for actual risk. It's almost cliché by now to compare reporting on terrorism to that on heart disease, but still a valid pointer toward severe failures of this proxy.

I suspect you may also be looking back on the 2009 H1N1 reporting and condensing about a year or so of reporting into one "media panic" blob. Comparing newspaper article records at similar times from the first known infections, it looks like COVID-19 reporting actually took off much faster and stronger in tone than that for 2009 H1N1.

I think a third potential problem, not at the time but right now, is a hindsight bias. Now that we know that the event happened, it's tempting to update too far in favour of it having been likely beforehand. There are hundreds of new diseases and variants infecting people every year. During the first few weeks to months, their pandemic potential is often completely unknown. Paying little day-to-day attention to each one is rational for the general public, though not for epidemiologists or public health officials.

As a general probability, by the time a disease of this sort spreads to your own area (and therefore you should be changing your behaviour), there is almost always a lot more known and published about it. There is a low probability that any given person is going to be one of the unlucky first hundred thousand infected out of 8 billion people on the planet. By that time it's usually pretty well known whether it's likely to be serious enough to take action.

So perhaps your estimation wasn't really as miscalibrated as you think.

I think the answer here is pretty cut and dry. 

"Media has a strong incentive to cause hype over things that aren't really dangerous trends."

This was your mistake. If  you didn't believe your sources were trustworthy, then why didn't you find sources you could trust? 

There were plenty of trustworthy sources of information early in the pandemic. A lot of credible people were talking about Covid a month before the mainstream media started prioritizing their coverage. 

The key moment was the realization that can spread easily.

We have much worse diseased by effect, like aids and ebola. Key thing is - we can limit the spread with moderate effort, even without vaccines. Once you could put together the belief that this one will not be contained, meant living in a different world and should have required adapting. At least internal.

Did you make a mistake?  What behavior do you wish you'd undertaken, and what is the prediction you failed to make which would have made it happen?

I started working from home a few weeks before my peers, and I got KN95 masks early.  And I had serious conversations to convince my folks to learn about grocery delivery and stop going to stores by early March.  But otherwise, mostly followed the general recommendations.

You extrapolated two times from a single example. That's generally bad when dealing with risky situation. Just because no catastrophe happened in one example from which you are extrapolating doesn't mean that there's no problem.

Part of the reference class for Covid was SARS. It's very unclear why the Flu which is a far more distant virus should be a better comparison then SARS. SARS causing long-term CFS was very worrying at the beginning of the pandemic. Fortunately, long COVID isn't as common and strong as CFS was for SARS but it was clear that long-term effects were something to worry about from the beginning.

The fact that pandemics were a big risk was a belief that a lot of people in our community held before COVID-19, to the extend that it was seen as a bigger GCR then unfriendly AI by many people in our census. Treating swine flu as evidence that pandemics aren't a huge problem seems to me generally bad reasoning about tail risk.  

1. It sounds like you were relying pretty heavily on the amount of alarm in the media as one of your main indicators of how much to worry (while using an interpretive filter). What you took from the swine flu example is that the media tends to be too alarmist, but you also/instead could've concluded that the media is not very good at risk assessment (and maybe isn't even trying that hard to do good risk assessments). The line of reasoning that this new virus is probably less dangerous than swine flu because it's less media hype depends on the assumption that the level of alarm in the media is strongly correlated with the level of danger (with a systematic bias towards exaggerated alarm); I think the correlation between media alarm and danger is not that strong in which case this argument doesn't go through. So, the media isn't that functional as an alarm, and you need some other approach for figuring out if there's a big problem. Really bad pandemics are possible, and the amount of alarm in the media isn't that strong an indicator of whether a new virus is likely to turn into a bad pandemic, so how could I tell if one is coming? You maybe could still use the media as an initial alert: the media is alarmed about this thing, and it is the sort of thing that has the potential to be really bad, so I'll take that as my cue to put effort into understanding what's going on (via some other approach that doesn't rely on the media). Or, you could try to be plugged into other information environments which are more reliable, such that you'd trust them more if they raised an alarm. I benefited from hearing things like this and this, and similar things by word-of-mouth & ephemeral Facebook posts.
2. It helps to think in terms of probabilities & expected values. Scott wrote about this in some depth in A Failure, But Not of Prediction. For example: If swine flu turned out to be unimportant after the media hyped it up, that gives reason to think that the probability that the next media-hyped virus will be really bad is more like 25% than 75%. But it doesn't give much reason to think that the probability is more like 1% than 25% - not enough data for that. And if you see the probability that a novel coronavirus will turn into a really bad pandemic as being as high as 25%, then it's worth investigating & preparing for.
3. It sounds like a big part of your lack of concern is that you thought the illness wasn't that serious, so that even if the virus became widespread it wouldn't affect you much. My memory is that this is different from the reasoning of most people who weren't very concerned, as it was more common to think that the virus wouldn't become widespread. So (a) this mismatch seems like a clue that something might be up, and worth looking into. And (b) I think there were reasons to think that the virus would be a big deal if it became widespread, e.g. the lives of people in Wuhan had changed in pretty drastic ways as a result of the virus.

Back in April 2020, I made an alarm bell for the next pandemic. It attempts to capture in checklist form some of the qualities of COVID that, in retrospect, could have signaled that this was no Swine Flu. I think there are basically two ways we could have avoided this mistake:

1. Understanding that we should be worried not only about certainties, but about risks. We were right to worry about the downside potential of Swine Flu, and we were just lucky that time. Likewise, we'd still be right to worry about the downside potential of COVID, even though Swine Flu didn't turn out to be as bad as we feared.
2. Looking at the underlying mechanisms that distinguish a pandemic potential from a non-pandemic potential illness, as I tried to capture in the alarm bell.

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