Fear of missing out (better known as FOMO) has been a constant worry of mine over the last few years. I felt like when I was studying or having a night in for myself with a bubble bath or some good old re-runs of Gilmore Girls that I was lame or should be doing something more productive. I felt like I needed to change the world in those few hours. I felt like I needed to climb a mountain or go bungee jumping or even just go out with my friends. I saw what other people were doing when I wasn't available to do the same and I wanted to be living in that moment too, but I had my own moment and I could have my adventures next week instead of right this minute.
FOMO is totally normal, especially in your early twenties/late teens and it's just the realization that you don't have the time now to go to every single party or rave or event that comes up. You can't go out drinking until 1am when you have an 8 am class and you have to prioritize instead of spreading yourself too thin.
Sometimes, this realization is disheartening, maybe even scary, but it's a part of becoming more mature. It's also a part of growing up and realizing you're suddenly an adult. On the other hand, realizing that there are important things that have to be done doesn't sound like the most fun option, but it's how you succeed in life and how you learn what is important and what is of value. If and when you do have time to yourself and you choose to spend it on some Ben and Jerry's and Netflix instead of dancing into the nearest club, do not let anyone tell you that you are "missing out" or you should be going out on the town. You do you and remember that you aren't always missing out on opportunities or occasions, it's just that you have your own opportunities that will come at different times than other individuals opportunities and they will cross paths, but never meet.
With growing up, FOMO shouldn't be FOMO anymore, but it should be the understanding that you'll have your days you can use to do whatever you want and that may be cookies and ice-cream or it may be tequila and vodka. A night in is not an opportunity missed and a packed bar is not an opportunity seized. Both have equal chances for mystery and intrigue and both can lead to a satisfactory conclusion. Growing up is realizing that getting things done is more important than making rash decisions or feeling left out of the fun club. It's also remembering that whatever form of "fun" you want to have is okay and sometimes it's just a bottle of wine and some white chocolate macadamia cookies and there should not be any judgment in that. So you take those shots or read the seventh book in the Harry Potter series again for the tenth time, but either way, make sure you are enjoying your moment and not worrying about missing out on other's moments.