A soldier is reading a book while off duty when he sees his sergeant coming. Everyone hated sergeant Thompson, he always had a big stick up his bum.
"Sergeant Thompson, Sir!" the soldier said, standing up smartly.
The soldier gladly returned to his book... until he realized the sergeant is still standing over him, staring at the cover.
"What's that rubbish you're reading there, private? Re..incar..nation? What's that all about?"
"Well," smiles the soldier, "It's pretty simple sir. Say you died, God forbid, and we buried you. Then a few months later grass grew on that plot of land. Then a cow came and ate that grass. As nature dictates, a few hours later it passes it through its stomachs and dumps it out on the ground...
Then I would walk by and say: "Hey Sarge, you haven't changed a bit!""