Such a thing has happened to me several times. there have been times that I planned to invest in the market and it happens that I missed out on my target and then I will feel that I have made a huge mistake because I missed the target I had, but at the end of the day I will realize that the market has dipped more than what it was earlier, and that means I now have a lot cheaper price or a lower entry to start from whenever I decide to go for it.
The best feeling comes when you finally invest and realize that you got in at the lowest point that the market would reach, and from there it starts going up and you start making good profits.
In recent times, I decided to invest with grin after theymos's good review about it. But, when I was checking its economic rules, I decided not to go with due to its massive supply. (Grin is a good coin for privacy reasons and not for investment purposes). I really had JOMO at that times.
This is something that DCA people constantly feel, it is not really something that we forget that easily. We invest into coins at any price, and that way we drop the average of entry we have, and sometimes we increase it, mine is low enough that I could profit at most prices and won't worry anymore but I know that I do not invest with all of my money and that allows me to make a lot of profit thanks to this.
Doesn't mean that I would have to have JOMO at all times, sometimes it goes up and I feel FOMO, but sometimes it goes down and I feel JOMO thanks to that. Long term investors feel the same way whenever the price drops, it allows them to get a better position.