The more information that gets posted, the worse it sounds. Hopefully you do move on to find a better fit for you, not one still hung up on her ex...

Fool me once: shame on you.
Fool me twice: shame on me.
Fool me thrice: I'm incorrigible.

Could be me, but I fail to see how what you say relates to what you quote?
There's nothing weird about someone having 3 exes unless they're 20 maybe.
At a certain age having 2-5 exes is pretty common.
And it also has no relevance to the OP not learning.

I thought it was obvious, but apparently it wasn't. Having too many exes seems, to me, to indicate that the person 1) has difficulties making up their mind or 2) is not thinking things through before entering into a relationship or 3) is rushing into a relationship before both parties are ready. I'm 82 and have only two exes (not counting one-night stands) and the last one was my wife. We were married for 46 years, until she died. Had I had many relationships, it would clearly demonstrate that I had an incorrigible tendency (and an inability to learn from my mistakes) to get into doomed relationships. BTW, having many exes tells me that there's a problem with at least one of the protagonists.