go into a pitch black room and lie down for awhile, and the worst case scenario is your brain will mull over the problem in a somewhat more spacious/relaxed way for awhile

I wonder if this is more or less effective than a short session of mindfulness meditation.

There are two problems I often encounter: lack of (1) attention or (2) energy. Interestingly, I've found mindfulness meditation to be highly effective with (1) but I haven't seen an obvious improvement to (2).

Perhaps, "lie down in dark room" could help for (2). I'll have to test it out!

On the other side of this, after realizing that people were willing to say no, I realized I could freely ask a lot more "spicy" and interesting questions to people. 

At the time, professionally, I entered a rather cagey/secretive finance industry so it was liberating to realize I could ask tough questions, and at worst higher-ups would give me a knowing nod coupled with a "I'm afraid I can't answer that one".

(Admittedly, this started to bleed into Slytherin-level tricks where I tried to watch for how quickly someone responded or denied. I certainly avoid doing that to random folks at a party, though!)