Yes, there's ADHD. I've seen it.
But, what's really funny about the vast majority of people diagnosed with it, it seems that the only time there are any "symptoms" is when the person is doing something they don't want to do. "I don't want to pay attention in math class. It's boring." That's not ADHD; that's normal. In those cases, it's a lack of personal discipline - they blame not paying attention on a disorder.
It's amusing when an ADHD kid stays home from school for the day, because "Grand Theft Auto 5 was just released!" They come back the next day and, "it was awesome! I played it for 16 hours straight and beat the game. I didn't even stop to eat." ADHD? Uh huh.
Now, I've seen ADHD when I coached soccer. Kid dribbling the ball down the field. On about the 4th kick, "butterfly!" and off he went in a different direction. He didn't catch the butterfly, because before he caught up to it, "flower!" He liked playing soccer, but was genuinely distracted very easily from the game.