Lingering effects of an attempt at bilinguality

I'm slowly losing all my Japanese and urgently need to read my textbooks again, lest my precious grammar slip away entirely, but there are parts of the language that are pretty much embedded.

For instance, whenever somebody tells me something that should prompt an "of course!", my first thought is "mochiron!" More or less every time.

I'm always tempted to just say that and save myself the .002-second step of translating between brain and fingers.