It's simple... Never judge the future on the past. In other words we learn as we grow. We learn from our past. If our skin becomes too thick, we get callous. Remember, the next person is just as human as we are, with the same frailties as we have. Consider the source, but allow for forgiveness. Try to allow for differences and try to keep an open mind. Try to let unimportant things in life bounce off of you....... set your priorities. Most people mean well. Remember: Everything happens for the best. It's a matter of moving your point of view around until you can see it.
It's not what you're called, it's what you'll answer to. Use your past to predict your future. Learn to recognize the warning signs earlier and don't let a relationship you see going nowhere drag on. People only have as much power over you as you give them. Mind over matter, you don't mind, they don't matter.