Why he compels you:
Damon: He was on a killing spree and had turned his emotions off so you compelled him to turn them back on.
Stefan: You got hurt by Damon and he didn't want you to remember Damon like that so he made you forget.
Klaus: he was going on a mission to kill someone and you wanted to come so he compelled you to stay in the house
Elijah: He tried to compelled you to forget him and to leave and never come back, but you were on vervain so he couldn't
Kol: He was being a dick and compelled you to do whatever he wants for a whole day
Enzo: He compels you to forget him and find someone who wouldn't hurt you
Tyler: Your a witch he can't...
Alaric: You lost your sister and asked him to take away the greif
