just like a new-born baby
 

Two elderly gentlemen from a retirement center were sitting on a bench under a tree when one turns to the other and says . . . "Slim, I'm 83 years old now and I'm just full of aches and pains. I know you're about my age. How do you feel?" Slim says, "I feel just like a new-born baby." "Really!? Like a new-born baby!?"
"Yep. No hair, no teeth, and I think I just wet my pants.