For me it's to do with work. I think of work all the time and I find it difficult to think of it in Greek. So I end up thinking about work, in English, all the time.

The problem is that I keep forgetting Greek words and I find myself using English expressions even when I speak in Greek, even when I'm not speaking about work. And then I start saying things I'd never say in either language. I'm particularly shocked when I make blunders like "περιφέρεια του κύκλου". I just hope it's too early for early Alzheimer's.

Oh don't worry, this happens to me all the time too. It seems to be normal.