I watched anime a lot in my youth and young adulthood, and found that after about 10 years of daily watching I could easily pick up a new show and understand the gist of what was going on. Complex words or exposition tripped me up, though. Nowadays I rarely watch anime but I’ve been studying Japanese daily on Duolingo for 4 years, and sometimes I’ll turn on a Japanese show as practice to try to recognize as many words as I can. It’s a totally different beast - Now I actually understand the nuances of sentence structure and have a much larger vocabulary, instead of just knowing a few key words. It’s a fun exercise.