If I ever fly business or first class, I'll just bring my own PJ's on board and change into them the minute I step foot on the plane. I'll also be sure to bring my fuzzy slippers too.

As far as caring what people think, I'm too mature for that. I've been known to walk around the streets of Manhattan in my PJ's (quick trip to Duane Reade to pick something up) and take out the trash in my indoor slippers. I walk around my house in PJ's, so that's what I'm going to be wearing if I'm traveling for a prolonged period of time.