You can't really predict accurately what will happen and when. I also sold a decent amount of Bitcoin back in 2017. I don't even want to consider what I've sold or spent back in 2015-2016.
On top of that, I sold at $25.000 and $29.500 respectively, I do regret it but there's nothing I can do to reverse it.
Regret would really be there because price is unpredictable and keeps growing and it cant be avoided that we might able to sell off lower on what are the numbers we are seeing now.
People shouldnt really mind off as long you are in gains then that what matter most and to think that we can still buyback when it pull backs or correct and sell it off later on.
This had been the behavior of the market since from the beginning.You wouldnt know on what would happen in the future thats why missing good opportunities are common.
People are just not really contented on what they had earned earlier if they do saw that the price shoots up to the rooftop without even considering or rethinking that what
if the price did go down after you had sold? For sure you would say that thats a good call or step you had made without regrets. lol