SOUTH BEND — Brian Kelly spent his 50th birthday Sunday likely wondering why he felt like years seemingly had just been shaved off his life.

Was the thumping in his head from ND’s apparent new third-down defense anthem — "Crazy Train" by Ozzy Osbourne (Da-DUMP, I-i-i-i, Da-DUMP, Da-DUMP, Da-DUMP)? Or was it simply more jabs at the second-year Notre Dame head coach and his football program from the victorious USC players?

"They just quit," Trojans linebacker Chris Galippo told Scout.com’s Dan Greenspan after the nine-point underdogs bullied the Irish 31-17 Saturday night, then crashed the AP top 25 at No. 20 on Sunday.

"That’s what Notre Dame football is about. They’re not anything like USC. I just love the way our team prevailed and put together a complete game today."

And this one from running back Marc Tyler, who banged the Irish for 67 yards on 13 carries while playing with the remnants of a dislocated shoulder: "We wore them out. They didn’t want to play no more."

While Notre Dame fans in recent years have viewed USC as sort of the Charlie Sheen of college football programs — lots of red flags and penalties from the NCAA, but where’s the real comeuppance? — the Irish had the opportunity to handle the job themselves Saturday in the first night game at ND Stadium in 21 years.

Now what should the college football world think of a Notre Dame program that flipped back to its mistake-prone split personality and compounded it by playing soft at times in the trenches against USC (6-1)?

Here’s how ugly today’s snapshot looks: The Irish received zero votes in this week’s AP poll. A Rutgers team that just lost to Louisville and an Illinois team that got punked by Purdue on Saturday both did.

There’s not a lot of opportunities for redemption over the next four weeks. Between now and a Nov. 26 date at No. 4 Stanford, ND’s opponents are a collective 10-18.

Overall, Wake Forest is the only school of the next four that makes the Sagarin computer ranking’s top 60, at No. 52. All of them have a national total offense or total defense ranking of 70 or below (out of 120 FBS schools). Two schools — Maryland and BC — have that dubious ranking on both sides.

Lose-lose?

"Quite honestly — I’m telling you the truth — the dangling of the carrot is more about a sound bite," Kelly said Sunday when asked what was left for his 4-3 team to play for now that the BCS aspirations have been tossed in the recycle bin. "It’s not what we do on a day-to-day basis."

He went on to publicly deflect the big-picture questions Sunday, labeling them as, more or less, sports-talk-radio fodder. Privately, though, he better be at least be dipping a toe in that pool.

At Notre Dame in 2011, it’s all about big picture. The reasons why some fans are so quick to want to light a fuse on the Brian Kelly experiment is leftover angst from the failed Davie-Willingham-Weis Eras.

There’s an ongoing perceptual tug-of-war over whether Kelly is the man who can bring ND football back and the notion that no one can.

Kelly’s right, that he can’t live in that world, but he better be aware of it, because his players cross through it every day. Recruits see it, hear it. The Irish fan base pays rent there.

So with an eye toward both the macro and the micro view of Notre Dame football, here are the most pressing questions Kelly must address once he blows out his birthday candles:

1. Is Tommy Rees the long-term answer at quarterback?

It seems like an odd question, given the toughness and the moxie the sophomore has shown and the better numbers he’s amassed early in his career when stacked up against some of the Irish legends at his position.

All of those players, though — the Theismanns, the Montanas, the Clausens, the Quinns — made steady, and often, dramatic improvement from humble beginnings.