I've had a fear of being left out ever since high school. It was actually around the time social media became big (Edit: So if you were left out, you would know you were left out from other people's posts). As a kid, I was always invited to my best friend's birthday parties, but then, I switched school systems and didn't have a best friend anymore.
My first book was going to be a YA novel called 7th Grade: Drama based on the worst year of my life, but then I realized how much I suck at fiction-writing.