I hate selfish people.

Everyone gets a little selfish at times.
We are all human.
You know, taking that last piece of cake without asking.
Waiting to pay someone you owe money too, few days more than you should.
Not calling a friend back because you are "tired" or just don't want to hear your friend tell you for the fifth time that she misses her ex-boyfriend.

Those are all acceptable.

When you don't bother to call someone, because you don't care how they feel but you still call them a friend.
That's the kind of selfish people I hate.