Yes, it is very important to sell your bitcoin in high price and buy bitcoin at lower price. If ever that someone did was the opposite thing, there is no profit earned in that. These situation is sometimes caused by panic selling, they think about bitcoin where its price is going to dump again. It is very important to stay calm when doing trading, one wrong move and I am sure that you will be in chaos.
What I am trying to say is do not be exaggerated about the things that you read online. One must not believe easily in anything that he might read or hear. Do not overthink and always do your own research before making any decisions to avoid any negative outcomes.