But recently maligned veteran quarterbacks Kurt Warner and Donovan McNabb are debunking that axiom at an alarming pace as they guide their underdog squads through the NFC playoff bracket.
Saturday night it was Warner hooking up with the freakishly athletic Larry Fitzgerald time after time as the Arizona Cardinals thoroughly de-clawed the Carolina Panthers in a 33-13 laugher. Today it was McNabb and the Philadelphia Eagles slicing through the defending Super Bowl champion New York Giants for their second consecutive road victory.
This sets the stage for a Sunday showdown in suddenly football-crazy Arizona for a trip to the Super Bowl.
I'll go out on a limb and say I'm not the only one surprised by the resurgent paths both of these signal-callers are on.
Now, he's playing in his fifth NFC championship game, an astounding feat in a league that has become rife with parity.
It doesn't seem that long ago that Kurt Warner was fumbling ball after ball as a Giant, babysitting the quarterback position for Eli Manning. And it certainly wasn't long ago that he was penciled in as the Cardinals' No. 2 quarterback between Matt Leinart.
But Warner is in the middle of writing another remarkable chapter in his book of fairytale comebacks. Nine years ago he was the former grocery store employee piloting the Rams' "greatest show on turf" to a title against the Titans.
Both of these stories bring to a light one of the things that makes us like sports in the first place: watching the mighty fall -- and watching them rise again.
It's a testament to the perseverance and dedication that brought them to the top of the quarterback heap in the first place.
And it sure provides some compelling story lines for those barber shops and pinochle games.