do the things they do occasionally, I wouldn't watch reality TV either but not all television is completely horrible or just watch popular movies, and bring them up in conversation.

Open yourself up to new experiences, get drunk at a bar, take a holiday somewhere interesting, pick a fight, read books you don't usually, watch mindless entertainment, build something with your hands, get a new hobby, take evening classes, learn to cook, try doing charity work.

Basically go ahead and try lots of new things because once your life experiences are more wider and more varied your ability to understand and bond with different kinds of people will be greater. Doing these things will probably improve your confidence as well.