You are not wrong however where that calm is going to come from? Expert investors or traders can remain calm even in the most difficult of circumstances as they know very well what they are doing as they have complete confidence and mastery over what they are doing.
That calmness coming from your knowledge beyond the business that you are taking will keep you in good position, knowing that even there's ongoing trial with your investment the chance that it will bounce back is possible, instead of panicking you'll just continue to monitor and if does you still have a good amount of spare money, more likely you'll buy more knowing that it's another opportunities to hold more.
But for a newbie trader that does not know what they are doing then this is going to be impossible as they will get scared at even the slightest movement of the market as they have no idea of what is going on, and as such it is impossible for them to remain calm when things really begin to go badly in the market.
Most likely it will going to happen with people who just been influenced by other people's success, those are after with gains without
doing some research about the risk that also inside this industry.