My biggest regret is probably to have invested in December 2017 in full bullrun (without having any knowledge of the financial markets, and even less of the crypto).

My second biggest regret is that I didn't sell early January before the crash prices (because I had still made some profits)
However I' m glad I did it, I learned a lot and I keep hope that things will improve (not too much choice I don't want to sell at a loss  )