What is with people who treat you like shit and then try to be all friendly with you later?

This has happened with quite a few of the many ex-friends of mine who treated me like shit and then seemed to think we could just be friends again after. All that categorically unforgivable shit they pulled? Meh. All water under the bridge. Lmao! I don’t know how forgiving they think I am. Or maybe, how dumb and forgetful they hope I am, but no. Just no. Get help. You’re a borderline sociopath who’s sorely out of touch with reality.

Has that ever happened with you?