I am literally the last person to give advice on this - I have been in an stable, pretty healthy relationship for 20 years. However, I do remember every serious break-up as if it were yesterday. S who called me from a bar to advise she met someone. M who called me after a business trip to advise we needed to talk, and I could go on and on. I recall the dates, times, weather and my location when I was notified - jesus, even now I'm putting up verbal blocks to limit my old feelings - using terms like "advised" and "notified" keeps it more clinical for me.
But ever time I wanted to know why - and every time I found it really didn't matter why. The purpose of my inquiry was to keep in contact with them - in my mind, if I could keep in contact, then there was a chance of getting back together with them. Sometimes it worked, but only for a short time. So, no advice - only a question: What is the purpose of trying to find out why and does it really matter? Okay - 2 questions.