try doing that without having your arms pointing forward and you will understand
He is used to it, so he has developed, exceptional balance---like a ostrich or chicken...or a emu. Ever seen a emu run around and a person is trying to catch it?
You can have this exceptional ability as well. Wake up in the morning, put on a t-shirt, but don't stick your arms thru the sleeves...and walk around...next...go get a bowl of cereal...try pouring milk...only problem is, you can't use a spoon to feed yourself...next, take a jog...oh, how are you gonna opening that door to get out? Ahhh, use your mouth (now aren't you glad your washed your hands after you took that shit last night?)...try not to trip...because you can't use your hands.
Repeat each day....and yes, you too will be just as frustrated and angry as he is...