Joy of Missing Out: You’re enjoying what you’re doing in the here and now and not on social media broadcasting or seeing what everybody else is doing. Opposite of fomo or the fear of missing out.
Guy #1: I had a great day, climbed a hill and didn't check facebook.
Guy #2: Good day?
Guy #1: Yea pure JOMO.
Short for "joy of missing out" and an antonym to FOMO, that means that you prefer being unavailable and deliberately risking to miss a party that could be the greatest of all time, because (to be honest) you really don't care and rather stay home and watch that new Sandra Bullock movie.