My biggest regret is when I got introduced to this back in 2012, I tried to buy £200 worth, the platform was down and I never bothered, just recently woke up to it again at over £4k per coin, it is a physiological thing where I don't want to buy at that price.
My biggest regret in bitcoin is why i did not believed this before...but that's was past...can't undo.
The good thing is I'm now here working for the success of myself in bitcoin.