A guy with a lot of friends who always goes to sporting events and concerts with friends when they have extra tickets. This kid has a life and is always busy and happy.

A stupid person; it refers to the lack of surface area on an individual's brain. The general thought is that the more surface area (wrinkles, creases, etc.) a brain has, the smarter the person is. Conversely, a person with a smooth brain (no wrinkles) has less surface area and would therefore be stupid.