Why does we always love the one who hurt us the most?

Everyone talks about love… love in different way different context with different people. I seriously do not know whether true love exist or not but, I had seen many time (I said I had seen not feel) that at the end one always end up broken hearted, whether it’s the guy or the girl. I guess if true love exists then this should not happen. However, it happens everywhere with everyone. With my cousin, my friend, my junior, my classmates, my so called sister blah blah blah.

Is love so strong that we lost control over ourselves? Alternatively, is it that we love the other person more than we love ourselves that we do not mind getting hurt repeatedly? We know will be disappointed but still we go on with it until he/she leaves us all alone.
Not only this we sacrifices many times, still the other person doesn't love us the way we love him/her. I do not understand why we have to go through all these. We have not done anything wrong to anybody but still we suffer. We suffer for the one we love the most. What have we done to deserve all these? Is it a big mistake to love someone so much… Moreover, love just happens you cannot do anything about it.
It hurts when you see him/her with someone else.. At that point, are we being selfish? Because we are not getting that attention, we want… or it is one-sided love?

At that point, you will make up your mind that you will not let he/she hurt you again but just a glance, a smile, or a word from the person will make all difference.
In addition, we always end up loving the person who hurt us the most.

: )