That's the other factor. At what point do you decide it's gained enough and make sure to cash in? How many people have the discipline to buy something at $1,00

That's the other factor. At what point do you decide it's gained enough and make sure to cash in? How many people have the discipline to buy something at $1,000 then watch it increase to $5,000 and not sell if it starts to come back down? Now imagine when it went to $20,000 previously and then back down to $6,000. There's nothing wrong with cashing out. Can't go broke taking a profit.