First things first, attention deficit hyperactivity disorder (ADHD) is real: It is a neurobehavioral condition that makes it exceptionally hard for people to sit still or concentrate on important tasks, and it affects 3% to 5% of children—30% to 70% of whom will continue to have symptoms as adults.
More about adult ADHD

ADHD (sometimes written as AD/HD, or referred to by its old name, ADD) manifests itself in different ways in different people. Children may act full of energy, or be unable to follow directions or pay attention in school, while adults may seem impulsive, irritable, and uninterested in work. Boys may refuse to sit still, while girls may daydream and stare aimlessly out the window. Only a doctor can correctly diagnose ADHD, based on a full examination of a person's symptoms.

The good news is, most people with ADHD respond well to medication and additional forms of treatment.