Actually I have a lot. Most people have. We regret eating that last slice of pizza. We regret losing touch with old friends. We regret speaking without thinking. It is all part and parcel of the learning curve of life.
Skipping merrily through my blogroll this week I came upon a comment thread which touched upon the nature of regret. The post in question was about infidelity and the comments were the usual self-serving, self-justifying witless selection of variations on "yeah, you go girl!"(Which roughly translates as "I don't actually give a toss about the rights or wrongs of the situation or the reality of the actual impact upon your homelife, I just want you to keep posting the titillating stuff." Most commenters either want a vicarious thrill or a justification for their own indiscretions. It is a mutual support group where self-awareness is handed in at the door in exchange for blinkers. But I become barbed and digress.)
One of the comments included the old chestnut that "you only regret the things you don't do." Which is utter, utter bollocks. There are lots of things I haven't done which I do not regret in the slightest. (I do not regret turning down the opportunity for a fumble with, oh, lots and lots of people. I do not regret deciding not to drive after a bottle of wine, or choosing not to do things just because everybody else was.) Conversely, there are lots of things I did do and regret mightily. (I shan't give examples, but I am sure you can think of a list of your own.)
Regrets are what differentiate the healthy from sociopaths. We make choices which harm ourselves or others and feel bad about it. It is not a badge of honour to regret nothing. It is a mental deficiency.