>>12017256>>12016653I am not
>>12016653 but I have a similar experience, albeit over longer time. I don't really consume much Japanese media, but I took two years of Japanese in HS over a decade ago. With just a loose background, basic grammar, I just put in some modest effort to grow my vocabulary gradually while watching vtubers. I'm sure I'm barely floating between N5 and N4 in actual skill, but I now able to follow along with collab banter unless it gets into some topic with really specific vocab.
I would never say "I know Japanese", and probably never will. But even my shitty low effort, I can definitely understand more than I ever imaged.