Me too, almost made me a fortune if I had hold on to it. Like in December 2020, Bitcoin was around $12,000 to $16,000 and I've decided to convert them to USDT. Until the big pump happened to $20k, then $30k and up to $60k. However, it would be smart for me to buy it early and sell as the price peaked to $60k. Now BTC is over $30k, and I believe that this will be the new bottom (or maybe not due to the death cross). Risk management is still important, as we should learn about diversifying our investments.
Timing is very important, if you have good knowledge and your assessment leads you to anticipate what the
market may bring you, the chance that you can sell it within the peak is very possible, though for now it's
all regret for missing that opportunities, you need to try working again and see if the same movement
will return back and give you the same chance.