Because they won't commute.
When they find the position, they can't find the momentum. When they find the momentum, they can't find the position.
The position of the dirtbag
Me: Because my bed is at home.
Sorry teacher I overslept. You mean you need to sleep at home too!
So he would stop getting lost everything he checked it.
Whenever he had the energy, he didn't have the time.
When he got the momentum, he couldn't find the position, and when he found the position, he couldn't muster up the momentum.
Because cross products don't commute!