As all people know, investors should always avoid emotional investing. But in most cases, investors' mood swings when the market is highly volatile.
People are not entirely rational. Feelings and other intangible stuff dictate them. Human beings are not able to act like machines and programs. It's nearly impossible for one to eliminate every shred of feelings. 
In that case, every investor must have been through "emotional damage" more or less in their trading journey...

They should create a phone too and call it the Pi.