paidinfull: Not much really, having been married for over thirty years to the girl of my choice, Felt a bit sorry for myself for a while after the split, at the time I felt I'd paid in full for not being more attentive to her.
Impressive. You've became self-aware. Perhaps there's a chance you could get back together now that you are aware of what went wrong.
Show her that you've learned not to take her for granted.
Show her that you're still in love with the girl you met 30+ years ago.
If the embers are still burning, try fanning them to see if you can get that flame going again.
This will only work if the above is truly and sincerely true.