I thought it was only me. Maybe there's some phenomena behind it. If there isn't then maybe I can develop some sort of theory. In the meantime, I remember once, at work, I was on the phone with someone who is now an ex-girlfriend, I ended up jumping into a work conversation and joking around with them real quick while she listened in on the phone. When I got back to her she asked me "Why can't you act like that outside of work?" I don't remember the excuse I gave, probably some nonsense from experiencing slight cognitive dissonance. But it certainly gets me thinking now.