I was stumped by the Captain Penny reference, so I turned to the ever-reliable Wikipedia and found out that <<Captain Penny [a kiddy-show host] would say at the end of every show, "You can fool some of the people all of the time, all of the people some of the time, but you can’t fool Mom. She's pretty nice and she's pretty smart." (This is sometimes referred to as "Captain Penny's Rule").>>
And here I had always thought I was quoting some guy named Honest Abe.