How to deal with condescending people

I would not appear to show a whole lot of interest in what they are saying. Smile and nod, and be polite, but not your warm and friendly self. Save that side of you for the people who really care about you. These people want attention, they want to be put on a pedestal. Don't give them the satisfaction. But also, don't act condescending towards them. You don't want to stoop to their level.