I feel the need to cook my hamburger even though it's already been cooked.
Why would you cook it again, what will happen to it?
It will be a strange and horrible tasting one.
If you cook it too long it will be hard to eat. You should just eat it as it is and trust it was cooked right the first time.
Nah, it looks good but I'm not hungry anyway, I'll cook it tomorrow.
I wouldn't recommend overcooking food. I understand you have the urge to do it, but it's not cannot be worth it. You'll end up just wasting the food, trust me.