I really don’t like the “my ex hurt me once and so that’s why I avoid love forever” trope

Now it’s not enough to make me DNF a book but oh my god it’s so annoying when the character has had one bad experience with an ex (and it’s not something traumatizing, that I’d understand) and suddenly they push away everyone else because they don’t think they can “love again”

Like I’m reading {The Charlie Method by Elle Kennedy} right now which I do like it a lot but one of the MMCs is so “hurt” over his ex from HIGH SCHOOL. Mind you he’s 21 and in college. Like…it gets to a point. So that’s why he doesn’t want to get with the FMC or doesn’t get involved in relationships and just sleeps around. Like there’s no way that you can get your heartbroken in high school (something that happens to so many people that it’s even expected because kids are immature) to the point that you push away an amazing girl! Like what??? Sorry, rant over.