E.P.
Honestly, I hope your son doesn't have ADHD and I certainly don't mean to make light of the subject. However, I have to laugh! If I had a dollar for how many of my friends w/ sons, ever asked that question about THEIR son, I'd be a rich woman!
I figured, if I was able to keep my son alive past 3 years old, I was very fortunate. It's seemed that no counter was too high of a jump, no shelf was too high of a climb! Nothing was too hard to take apart - and he could figure out every lock in the house! It was the skinniest time of my life. He was in constant motion, and so was I, chasing him! And he was such a happy kid!
He's ten and is a very good student and still in constant motion - Excellent mechanical ability and is still very happy and adventuresome. Sadly, I am no longer "skinny"!
So..yes... he sounds normal.