Some call it The Honeymoon Phase or puppy love. Others mix it in with infatuation or limerence. Views on new relationship energy (NRE) vary, from seeing it as immature to completely normal to a little unhealthy. Regardless, NRE distorts your perception of the person you've just started dating. This can be thrilling, though at times a little scary. It feels like living in an illusion that you know is going to be shattered sooner or later.
The Baader-Meinhof phenomenon (also called the Frequency Illusion) is what happens when you learn about something new, then start to see it everywhere. There is a lot of similarity between what happens here and in NRE, to the extent where NRE can effect your emotions in the same way that Baader-Meinhof effects your mind. It is the feeling of every love song reminding you of your new beau, or every book, movie, and band you like seeming like something to recommend to them. This is also partly because NRE is often when you learn the most about a person. You find out that they like sushi, and suddenly every sushi restaurant seems like a good date location. Often, you associate the person with happiness, and feel compelled to share other things you associate with happiness with them.
The new feelings that come up during NRE function much like the new idea in Baader-Meinhof. When you notice things your new partner likes or would like everywhere, you don't often think of it as "wow, the things this person likes are everywhere", but instead it feels like you can't stop thinking about them. And of course, if you can't stop thinking about a person, this is evidence that you must like them a lot.
The things you learn about a person's traits play into this effect as well. If your paramour is particularly smart, a lot of the things they say or write might draw attention to this. Especially if you were friends with the person for a while before the relationship started, you may feel like you didn't realize how funny, intelligent, or attractive the person was. The emotions are so new that it feels like the person is much more amazing than you ever gave them credit for, and you are only now starting to notice. Part of this is also due to fundamental attribution error, which is what's happening when we assume a person is helping their friend move because they are kind, without considering that their friend may have bullied them into it, or they may owe their friend a favor.
Personally, I feel like viewing the emotions that come up as part of NRE as similar to cognitive biases helps normalize it. It works in similar ways, and although people work on reducing the negative effects, everyone has biases, cognitive and emotional. As such, your awareness of your emotions is as much a tool for growth as your awareness of your thoughts.