I learned about this word today too. It stands for 'Joy Of Missing Out".
You were thinking of buying a coin and later that coin dumps to oblivion. That's JOMO!
^ I have been experienced the same on this and fear will begin because thinking that it is possible a trap and after investing the price will drop.
It will only create a fear to invest not the excitement because you know the possibility that anytime the price will drop right after you will invest and probably it is a good time if you will wait until there is a correction. If you believe in the coin that you want to invest in, even if you are JOMOed still that is worth it to invest if the coin has potential.