I often forgive many people in my life and many people call me a fool for it - but I think that those who forgive rarely are the fools.
The saying, "Forgive but never forget," is my life motto. Why? Well, I believe that if you go around hating, or at least despising, someone for a wrong that they have done, you will soon run out of people to hang out with. It's even worse if you have to stay in an area in close proximity to them.
While I do forgive, or at least am open to forgiving someone, I never forget it. I never forget that I had to find it within myself to forgive them. Because, "Fool me once, shame on you. Fool me twice, shame on me."
I always keep my guard up, even years later because that trust that was built up so high once was often broken by a simple syllable. Even after I forgive them, I try to rebuild that wall of trust, but that wall of trust has holes in it. Holes that I can peek through as an observer of every single move and word and judge whether or not that wall should come down again.
Each time I choose to forgive, however, the wall comes up with more and more holes for me to peek through until that wall of trust becomes that a sheer veil of trust. That sheer veil means I might run to you in my time of need, but I wouldn't trust you to feed my cats when I'm out of town.
That being said, I don't always forgive people. Cheat on me? Nope. You're lucky I don't egg your house (even a year after I find out about that), let alone involve you in my life long enough to forgive you. Same with other major trust breaking deeds, like physical fights and distribution of sensitive material - basically deeds that can easily put you behind bars, but I don't have the money to legally fight it.
Why should you forgive? Because it cleanses the soul. When you forgive someone you will no longer lose sleep over them, no longer take time and money consuming detours trying to hide from them and avoid contact and your back will literally allow you to finally sit up straight again as the burden is taken off your shoulders. It allows you to be the better person. It allows you to be free of your manacles. It is worth it.
So, for your mental health and for every positive aspect of your life, always remember, "Forgive but never forget."