Once you start collecting thoughts, ideas, knowledge, and inspiration, you might want to capture anything that resonates with you.
Don’t forget that note-taking and Personal Knowledge Management, in general, are mere tools. They exist to serve a purpose. If you capture information just for the sake of capturing it, there’s no point. It can still be interesting as a recreational activity, and there’s nothing wrong with that.
Don’t fall victim to the collector’s fallacy. Make sure what your goal is when you capture something.
Ideally, you only want to capture what will be useful to you at some point. Hoarding content needlessly is useless, and can even be detrimental to your success.