Do you obsess over the last verbal interaction you had?

For example, I may have a small interaction with a cashier and say something like "No thanks, that's all I needed." Later in the car ride home I'll be replaying it in my head wondering things like: how was my tone? Did I sound too curt or mean? Did that sound stupid... I mean it's not like I really cared about the person and if they thought bad of me who really cares but I can't stop repeating the phrase and analyzing.