There are many people who don't have any idea about coins. They don't know what projects are behind the coins, and they want to buy just because others are buying. If they don't know enough information they can't believe just because their friends believe in it. That's why many waves of panic when they see that the price is going down while they expect the price to go up.
If you know the project and belileve in it, you don't panic even though the price goes down for a while.