I also learn from failure. When the profit reaches 20%, I will withdraw the profit. If I lose 20%, I'll sell. Sometimes it's hard to do. When I sold, I would complain that I could have made more. This is wrong.
When you lose 20%, it is better to hold and not sell it for that price because losing 20% will be big for you. Perhaps, if the price is down 10%, you can sell bitcoin and buy back at a low price. But we know if the price will still go down or it will be back to the high price. And if you think that selling at losing 20% is the best thing you can do, you can do that. But you need to think twice before you sell at a loss. So hold bitcoin like Gollum will be the best thing that we can do in the bear run.