I remember seeing a meme where a teenage boy came home from school and told his mom that he asked a girl out and she said no. His mother then said, "You know what you have to do now?" And his reply was, "Yes, if at first you don't succeed, try, try, again." And his mother said, "No. You asked her a question and she gave you an answer. Leave her be."

I would take it further and say, "If a man asks a woman out and she says no, and you see her, don't open the conversation. If she says hello, say hello back. She might genuinely appreciate your friendship but that might be all she wants." I view friendship like this, "Saying hello is an acquaintance. Saying hello and making small talk on more than one occasion is small talk. Enjoying conversations is stronger friendship. If, however, you go beyond friendship and the other person doesn't want it, they might avoid you altogether."

This guy sounds like he had a level of entitlement that was dangerous. One thing that I have found is, if someone talks continuously about their exes, it can be a red flag.

You dodged a bullet literally and figuratively.