When Tony Stewart walks into a room, the atmosphere changes.

This is partially because Stewart likes to sneak up on unsuspecting people and pinch their rear ends or goose them. But mostly, it's because Stewart, more than anyone else, is NASCAR's "Larger Than Life" driver.

No, that's not a joke about Stewart's weight. Rather, the driver/owner of Stewart-Haas Racing often seems like a movie character brought to life.

He's as pure of a racer as they come. His peers tabbed him as NASCAR's most talented driver because he drives anything with four wheels - and usually wins in it. While other drivers spend their off-days lounging by the pool, Stewart hops around the country from one place to another, jumping into a dirt car with no practice and leaving with the checkered flag.

At the same time, his personality is the stuff of legend. He's famously combative with reporters and has little tolerance for stupid or unoriginal questions, but he's also one of NASCAR's most kind-hearted individuals. Many of his charitable acts happen behind the scenes, like lending his personal plane to a family who has suffered a tragedy.

Even after being in the spotlight for years, Stewart remains somewhat of an enigma. Predicting which version of Tony will show up on a given day, hour or minute is more difficult than predicting the weather.

So why is Stewart larger than life and not Dale Earnhardt Jr. (NASCAR's most popular driver) or Jimmie Johnson (the only driver to win five straight championships)?

It's because of the way they carry themselves. Earnhardt Jr. has more fans than Stewart, but he's often quiet and can be somewhat shy. In street clothes, Earnhardt Jr. can blend into a crowd and practically disappear - which is exactly how he likes it. He's been known to park a street car outside the track and walk among the fans after a race, unnoticed, in order to get a leg up on traffic.

And in Johnson's case, his friendly and accessible nature doesn't lend itself to an awe-inspiring presence. When he enters a room, it's more like, 'Hey Jimmie!' than 'Wow, there's Jimmie!' Johnson will be recognized as a legend many years from now, but doesn't have that vibe just yet.

You can tell Stewart is in the room, though, without even turning around. There's sort of a murmur that comes with his arrival - accompanied perhaps by the yelp of a goosing victim – and all eyes are quickly focused on the driver.

Maybe it's because you never know what Stewart is going to do. Maybe it's because of his sharp tongue and acerbic wit. Or maybe it's just because Stewart is a character who is truly larger than life.