trust

is it easy to give trust to people who have never hurt you?  how easy is it to give to people who have hurt you?  do you keep giving it?  does it have to be earned back? does that mean that if you maintain a relationship with some who has broken your trust that you have loaned them trust? how do they ever repay it?   should they have to? does it actually have nothing to do with the other person and everything to do with myself?  should i trust my emotions or my brain? should i expect less? or more? or nothing?