One of my biggest regrets with bitcoin is that last year i got like 5 btc on my wallet and i sell it to cash.
If i just waited one more year i could have more than $18k at the moment instead of $2,5k

but i think that one of the biggest regrets of the whole community is buying bitcoin when we hear from first time about this coin. When i hear for the first time, it was around $150 each one i think.
Sad story
Same also as mine last two months ago I sold my coins at the exchanger but in a low sell value due to panic of price drop down. After all I realized it was a mistake and my regrets was already came out, because after several months the token I had sold at a higher price value And it even tripled the amount which I sold that time. We could not be certain all the time on our decisions, and many factors will be considered and based on the regrets we encountered I thinks emotional management must be always considered.