Second chances

Do people really give second chances when it come to relationship or friendship? From experiences I have given my share of second chances to others. But when it comes to getting a second chance,  do you really receive a second chance? 

I wonder about this all the time. In new a relationship or friendship you expect to start slow. You normally have walls up so the new person in your life does not really know the real you. Yes recently this really happened to me but the outcome was tragic. Now that things has settled down, I decided to let the other person know about the real me.  You know that didn't even work either. Now I sit here figuring out that sometimes second chances does not exist. Or the other person does not really care enough to really see reality. Am I wrong in thinking this way?  What do you think about SECOND CHANCES? Do you give your all to the new person you come across? If so, how do you handle when the relationship or friendship goes sour? I would love to hear how others deal with new relationship or friendships.