Do you have anyone who likes to go home early and not take part in the fun?
In our band it's our drummer...he only drinks tea, he likes to go home literally the minute he's played so when we're mingling with the audience he's pestering us to go, he's always asking when we're getting paid lol, he doesn't come to rehearsals, he never likes to come for band drinks or trips out to try and get new gigs. We only ever see him when we go out on gigs.
Having said all this, he's a great guy and we wouldn't swap him for the world, lol!
Sometimes it just makes me wonder whether other bands have a weird member like that?