Forgiveness? What a concept!
I prefer to outlast those who've harmed or offended me, then remind those who knew them of exactly how mean they were.
This is kinda easy, especially if the only encounters you've had with such a person involved harmful or offensive acts on their part, and doubly so when you can produce valid documentation to back up your claims.
Of course, if someone ever issues a sincere apology, then I feel the obligation to at least act as if I've forgiven them, but let them screw up just once more, and ... 
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The mere fact that science may not yet adequately explain an object, event, or experience does not mean the immediate explanation should automatically default to a conspiratorial, extraterrestrial, paranormal, or supernatural cause.