Chocar literally means "to crash." For example, it's used to describe an unexpected meeting between two automobiles. Colloquially, it means to clash or annoy. Someone acting obnoxious or confrontational is frequently described (at least in Argentina, where I learned the language) as chocante. So:
Me choca que cuando estoy dormido suene el teléfono y me despierte.
It annoys me when I'm sleeping and the phone rings and wakes me up.
Me choca tener que ir a misa todos los domingos.
Having to go to Mass every Sunday bugs me.
Me choca que siempre me des la contra.
I don't like how you always contradict me.
Tú me chocas.
You bother me.