My questions on this would be…did you ever have a conversation with the young man in high school in which you told him what you needed? Do you really think it was cool to dump him like that without giving him a chance to grow in the relationship? It’s hard to imagine that anybody would ever learn and change as a result of doing what it sounded like you did, and just dumped him once and for all, no possibility of any sort of a second chance, out of what would have looked to him like the blue?
I’m glad you got the relationship you wanted later…but are you sure you might not have got it with this guy from simply talking to him about learning assertiveness?