You see the time to buy is always when there is a drop and everyone else is panic selling. meaning ~2 days ago when price was $3600 lower than current price. And time to sell is always when all the buys have stopped and the price is on top getting ready for a correction. or in case of bitcoin getting ready for a large scale FUD. Usually people sell when it is too late and price has already dropped 30% and everyone is saying "Sell Sell Sell" and they buy back when the rally ended like buying at the top of it at $20000 last month! Of course when you buy you can at least be sure because of how bitcoin is, price will eventually go up so there is no last chance for buying, technically speaking!
Most people are just actually following what others are doing. Mistakes can be the best way for these people to get to know cryptocurrency and how to play the game well. Of course, if one is not into trading and just hodling whatever he got then it is just fine. I should say that when I was also a newbie I have been a victim of myself...selling at the point when the price was already sliding. Well, this is life, we have to pay our tuition fee. Trading is not an easy thing to do much more if there is no one guiding a person and just relying on his own.