HOUSTON -- With child-like glee, Houston Texans defensive end J.J. Watt couldn't sleep last night. He tried for a couple of hours, then gave up and did one thing he knows best how to do. At 3:05 a.m., he drove to NRG Stadium for a workout.

There was just one problem. The Texans had changed the passcodes to get into the building, so Watt was locked out. He stood there, half-wondering if someone played a trick on him and he didn't actually just agree to the richest contract of any defensive player in NFL history.

He got in by 3:30, as a woman cleaning at the facility opened the door for him. At 4 a.m., someone texted Texans general manager Rick Smith a photograph of Watt back at work.

On Tuesday, Watt swore he wouldn't change. He swore money wouldn't change him, because he never chased money -- he chased greatness. Fourteen hours before a news conference to announce his $100 million contract, Watt proved that. He will always be trying to prove something, and he still wants to improve until he's once again underpaid -- he said that with a smile knowing how much more difficult that will be now.

It was easier to work hard enough to be underpaid as a pizza delivery guy, the job he took after he left Central Michigan to earn some money for when he walked on at Wisconsin. There, he declared to an employee charged with training him that he was going to play for the Badgers in six months.

"He looked up and down and told me I was not big enough to play for the Badgers," Watt said.

But he walked onto Wisconsin's football team, promised his parents he'd earn a scholarship shortly, and did just that.

By the end of his college career, he was one of the premier defensive ends in college football, a player who was only going to get better. How much better? The team that drafted him didn't know. If they had known, they wouldn't have even considered another pass rusher. Watt became the perfect fit.

He learned, he improved, he proved his worth as a first-round pick. Then he proved his worth to the rest of the league, becoming the NFL Defensive Player of the Year in just his second season.

"Now he’s the best and he’s going to do nothing but get better because he’ll be out there working every day, doing everything he can to improve," Texans owner Bob McNair said.

McNair joked he was late to the news conference because he was pawning his wife's jewelry to help pay for Watt's new contract. More seriously, he said the very reason he entrusted Watt with that record deal was that he knows Watt doesn't play for the contract.

"When I was talking to my parents. They said, ‘Well how does it feel?’" Watt said. "And I said it feels awesome. But at the end of the day, it really doesn’t feel that much different because it’s not going to change who I am or the way that I live my life. I’m going to go out there every single day and chase greatness."

It started with a little bit of insomnia, a way through the locked doors of an NFL stadium where Watt is a king in so many ways.