6 happy years
(updated with a slightly better scan)
"Mama, what is a wedding anniversary?"
"Well, six years ago today your daddy and I...."
"No! I don't mean when you got married! I mean, what is a wedding anniversary?"
"I'm telling you: our wedding was when we got married, and... OK, our anniversary is kind of like the birthday of our wedding."
"Oh! Did you get cupcakes?!?"