On a flight to New York City a few weeks ago, I sat next to a very chatty man who asked what I do. We got into a brief discussion of young adult literature, with me explaining a bit about what makes it different and why I would be drawn to it. Now, weeks later, I’m realizing that age isn’t the most important indicator of what makes a young adult novel. Instead, I see that position taken by angst.

In essence, angst is a feeling of anxiety about your life or situation. (This definition even used teens as an example of angsts. While worrying about your situation or life isn’t exclusive to teens, it’s what defines the age. So much happens but even more is uncertain once you hit puberty. It’s not just hormones, either.

Everything is neatly planned for kids up until they reach the age of 18, when they’re truly let loose on the world for the first time. They move out, go to college, make life choices that generally affect their remaining years on Earth. The thing is, teens don’t all automatically know what they want from life and plan to do once they graduate high school. Those years leading up to graduation can be incredibly difficult and frightening. Then add in hormones and dating and family. It’s a miracle we survive.

What sets YA apart from adult books with teen protagonists or middle grade stories with characters who are slightly older is the fact that angst is a large part of the main character’s struggle.

A few examples:

Twilight: Bella is uncertain about herself and her life after she moves in with her dad. Enter the eternally angsty Edward, who shows her what she wants, but she still has to fight to make it all happen. Take it away, and she’s left adrift.

Paranormalcy: Evie’s had her entire life plotted out for her, but she’s still not content. When uncertainty about her work and life rears it’s head, she’s tossed head on into angst about her entire identity.

Harry Potter: While the books obviously started at middle grade, Rowling does an excellent job with showing the increasing angst of Harry as he tries to figure out his future—if he even has one—and his place in the world. Order of the Phoenix epitomizes this inherently teenage angst.

I find myself drawn to YA novels for many reasons, but a large part of that is the feeling that I still don’t have a clue about what the future holds for me. Though I’ll turn 30 in a month, I still feel like I’m in my early 20s, exploring life and all it has to offer. Heck, I’m in France right now taking an extended working holiday that hards back to the study abroad I took in England during college. For me, that angst is still there, but now I have a better grasp on actions and consequences and the future.

So tell me what you think. Is angst the defining factor for YA books? Or is it something else?