INDIANAPOLIS -- Someone forgot to tell Jim Harbaugh he's supposed to hate this stuff.

Throughout the month of December, the lines coming out of the NFL were all the same. Recruiting's too much work. It takes too much time. It's too tedious. It's frustrating. It's too hard to predict and it's too much of a headache.

Why would a coach with elite NFL success head back to the college ranks, where he'd have to revisit methods of teaching players to walk before they can run. Too time-consuming. Too exhausting.

Why, in the hell, would Harbaugh do this to himself?

I'll bet Christian Gelov knows why.

Gelov, a diminutive, yet feisty, quarterback in the class of 2020 was on the field Thursday at Bishop Chatard High School in Indianapolis. He's about to be an eighth grader. He's not in high school yet. There's no promise he'll ever become a college prospect. Maybe he will be, but maybe he won't. Either way, he loves football and he showed up on time.

That was enough for Harbaugh.

On Thursday, Michigan's coach spent as much time working one-on-one with an eighth-grader as he did four-star passer Brandon Peters, who will wear a Michigan uniform in 2016. Every kid who paid his $45 got the full Harbaugh treatment, from start to finish. He was hands-on, he was encouraging, he was engaged, he was smiling, he was invigorated and in his element.

Frankly, Harbaugh appeared to have more fun than most of the kids. And if his demeanor was all an act, then he can pick up his Academy Award at Michigan's next satellite camp stop.

"This is the greatest sport ever invented," Harbaugh says. "Nobody will ever play four years of high school football and look back and say 'I wish I hadn't played football.' You ever hear anybody say that?

"It just doesn't get said. Because it doesn't happen. Football is darn good for you. Darn good for you."

In December, Harbaugh talked about his own personal "homecoming." He returned to Ann Arbor and to Michigan.

But deeper than that, he returned to his own personal wheelhouse as a football coach.

He may stay at Michigan forever, he may not. But watching Harbaugh bounce around the turf in northeast Indianapolis on Thursday proved that the college game suits his personality and mindset better than anything.

At its core, Harbaugh's "Summer Swarm" satellite tour is a recruiting camp. Michigan can't, technically, discuss recruiting with players at these stops, but they'll get to put in three hours of undivided face time with elite athletes across the country over the next week. There's a serious benefit to the program, and the entire idea was creative, smart and absolutely the right thing to do for Michigan at this point in time.

But for Harbaugh, it seems to be more. For three hours, he gets to do what he seems to love more than anything else on Earth.

Teach football.

His drills are unique and often odd, but they're always competitive and always hands-on. And his energy never stops.

Dressed in long sleeves and khakis, Harbaugh sprinted through quarterback demo drills with sweat pouring down his brow and a smile on his face. He drew passing routes on his hand during skeleton throwing drills. He showed players how to properly stretch, how to throw on the run, how to catch, how to play "Peruball," how to line up and how to do it all with relentless energy and every player on the field lapped up every second of it.

Apparently this is what the whole "enthusiasm unknown to mankind" thing looks like.

"I just want to tell you guys how much fun that was for me," Harbaugh says to anyone willing to listen. "Just to be outside with guys who like football. You're strong, you're fast and you just like to play. I like guys like that. That's how I was.

"Just out here playing, not thinking about anything else. That's football, and then you'll sleep really good tonight. ... Just out here having fun, playing football."

When dust hits the floor, winning might be the thing that drives Harbaugh the most. His competitive drive is legendary, and borders on obsessive.

But if winning takes up a majority of his brain, teaching and engaging in the game of football fills the rest.

At the college level, Harbaugh gets to be around the game in its rawest form. He gets to mold players. He gets to see the light go on when a quarterback figures out a read, or when a lineman masters his footwork. He gets to be around young people, whose energy and relatively untainted passion for the game equals his own.

In the NFL, he gets to manage. He manages elite talent, sure. But he also manages egos with paychecks, and owners with agendas, and general managers with control. The last thing he gets to do is teach, and engage and enjoy.

I've been to plenty of camps like this in the past. Where big-time coaches or star athletes "run" an event by standing on the sideline, schmoozing with adults and asking for the time before giving a cliche 2-minute pep talk at the end.

On Thursday, Harbaugh didn't wear a watch. He never touched the sideline. He never stopped teaching and he never stopped smiling.

"I had a lot of fun, personally, those three hours just flew by," Harbaugh says. "Some of you guys got here an hour early, so it was four hours.

"Just flew by. That's football."

This is Harbaugh the college football coach, seemingly having the time of his life.

And despite what the NFL told you, this is Harbaugh at home.

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