Not everyone will understand your nature, though, even if you try to explain it. When Robby, a teenager from New Hampshire, first learned about introversion, he felt a great sense of relief. He had a tendency to turn quiet in large groups, and although he’d always felt comfortable talking and joking with his closest friends, he had a limit. “After a couple of hours I’m like, ‘Whoa, I can’t do this.’ It’s draining. There’s a wall that goes up and I don’t want to talk to anyone. It’s not physical exhaustion. It’s mental exhaustion.”