There was one time when I thought I should leave a guy standing - every bone in my body was shouting out to turn on my heel and get out - but I didn't. I could have saved 4 years of unhappiness and being walked over, and it was so early on in our relationship I couldn't decide one way or the other and stayed. What a to$$er he was!! And I was only 19 and knew no better.
That was my "wish I hadn't." Now for the "wish I had." The most gorgeous man in the world used to pursue me, and I was so convinced that he was taking the mickey, that I used to avoid him. (doh!) I was at work, in a bar, and his brother came in to use the phone and tell him to come out. I heard him say "Yes, she's here" then turned and said to me "xxx wants to talk to you." I thought he was taking the mick aswell, so I pretended to be too busy to talk. He lived away, and I never really saw him after that because it was just before I moved up here.
I've sort of regretted that for 15 years, but all the while not forgetting, ever, that I wouldn't have found mr nutgone and had my beautiful children. I just daydream about it every now and then, as a little "what if?" sort of thing....