Thanks for your reply!
I'm also not really studying for a specific JLPT test. Just for fun, really! :D
[...] do you take in a lot of (comprehensible) input?
I'm actively reading Satori Reader stories on my commute and also occasionally read NHK Easy news.
I've also tried watching gaming videos, streams, etc.. But those are still way above my level. If I had to guess my comprehension level for those, I'd say I understand around 15-20% of the words. If they have subtitles baked into the video, then that helps a lot as well.
The only videos I am able to fully understand are the videos by a YouTuber called Shun.
I came to realize that I don’t even know why I say certain things [...]
I've noticed this after learning English. At some point it just switches over and you don't really have to think about it. Though I feel like it's quite a lot harder with Japanese, since it's so linguistically different to English.
I'll definitely get some more input in! Thanks for your help! :D