They don't get better with age
Your dad doesn't watch when I ride my bike.
Thanks for sediments
Sorry, the punchline is the joke. If you don't get it, ask your dad.
Humphrey. (I was told this joke by an actual dad, it was his response to one of my jokes)
Because they can lie about their age!
I said, "I'm five." He said, "When I was your age I was six."