You are living in a fantasy if you think that afterwards you can figure out that you should have had sold at $108 and bought back at $74k.. Guys who think like that don't tend to have a lot of bitcoin, even if they had gotten into bitcoin in 2015.. They were too busy fucking around trying to figure out when to buy BTC and when to sell BTC rather than focusing on ongoing, persistent, consistent, regular and perhaps even aggressive buying of BTC.
I agree with you JJG you have made everything clear now, anyone who is trying to figure out when to sell he or her bitcoin investment in other to buy back cheap is living in fantasy, because he or she is likely not buy back bitcoin cheap rather he or she will end up buying bitcoin at a higher price, so instead of trying to figure out when you sell in other to buy back cheap it will be better you keep on accumulating bitcoin the more instead of trying to figure when to sell in other to take profits and buy back cheap.
In addition, they might even end up nothing and losing out of buying and accumulating, those set of persons are not ready to invest in Bitcoin, instead they just sit down at the edge and keep watching the price of Bitcoin until they miss out