Allow me to explain my situation: I know an alright amount of Japanese. Enough that I can watch fairly straight forward shows without the need for a translation. Beyond that, in shows where the assistance of subtitles is needed, I can generally grasp anywhere between 50 and 75 percent of what’s going on without the need for a translation, and this is where the problem starts.
Maybe I’m just weird, but I have a Japanese “switch” and an English “switch” that never really turn off, but get set at different priority levels depending on what’s going on. At least, that’s how I make sense of it. When I’m watching anime, these two switches sometimes come into conflict. For instance, I can understand most of what’s happening Keion! raw. However, I found that while watching it raw, I miss a lot of the punchlines. So watching it subbed, a lot of the dialogue seems redundant, because I’m taking it in on one level in Japanese, then taking in the translation again in English. In the end, I’m only really doing it to catch those few jokes that I missed, since that’s the main selling point of the show. It is a comedy, after all. So, going back and doing this almost seems like a chore when I understand most of the dialogue.
That said, this only really happens to me if I’ve seen the episode raw beforehand. As such, I have opted to only watch Keion! translated.
And even then, it’s rare. If my first outing with the show is the translated version, the chances of that sort of interference happening is even lower. However, if I’m particularly tired and don’t feel like squinting at words on a screen, I’ll just ignore the subtitles at times. But that in turn doesn’t work terribly well when the script suddenly throws unknown vocabulary at me, because then I have to quickly switch back to English-mode, which in some ways takes me out of the experience.
I can only describe this feeling as “almost” knowing a language. It’s generally not too bad, but I suppose if you’re a weirdo like me, it does sometimes get in the way.