Whole-Wheat Bread

Two very elderly men were having a conversation about sex: 

1st: Yessir, I did it three times last night with a 30 year old! 

2nd: You're kidding! I can't even manage to do it once! What's 
your secret? 

1st: Well, the secret is to eat lots of whole-wheat bread. I'm 
not kidding!  

So the second old man rushed to the store. 

Clerk: May I help you? 

Old man: Yes, I'd like four loaves of whole-wheat bread, 
please. 

Clerk: That's a lot of bread! It's sure to get hard before you're 
done! 

Old man: Damn! Does EVERYONE know about this except 
me?