It also depends on the topic of conversation.

If the convo starts, "Oh, you're a therapist?! Tell me, what do you think of this? Blah blah blah..." it might be easy for someone to kick into work mode and start speaking like a T. (Not implying that's what you did, mcl, just an example.)

And, like learning1 said, if you spend all day communicating in a very specific style, and your training and practice has shaped your mind in a specific way, it's not unlikely that you're going to carry that with you. I know a few attorneys, and they all speak like...attorneys. I have a relative who's a doctor, he can be very brusque and to-the-point in conversation. There has to be a good amount of alcohol and an interesting conversation before the "real" person comes out to play.

I think it's an occupational hazard.