As it turns out, you can teach an old railroad new tricks.
Who says you can't teach an old dog new tricks?
They say you can't teach an old dog new tricks, but I'm living proof.
Who ever said "It's hard to teach an old dog new tricks" was right.
Just a matter of trying to teach an old dog new tricks.
"They're really nice and they teach tricks that you didn't know."
Apparently, you really can't teach an old dog new tricks.
But the professor can teach tricks he couldn't do himself.
Who said you couldn't teach an old dog new tricks?
They say you can't teach an old dog new tricks.