After a redshirt freshman season in which he completed 295 passes for 3,706 yards and 26 touchdowns against nine interceptions in 2012, former Texas A&M quarterback Johnny Manziel won the Heisman Trophy.

Since that December night when Manziel made history as the first freshman ever to win the Heisman, his life has been watched, eligibility debated, decisions questioned and Tweets scrutinized.

"I don't think you can name another person who's gone through college and been through some of the things that I have, and I'm well prepared for that," Manziel said after his pro day workout Thursday. "I've had to talk at a lot of places, had to do a lot of things that a lot of people in my position wouldn't have had to do, so I think it directly prepares me for what's going on in the future. These guys have directly prepared me for this stage and what's going on.

"The hardest part is probably coping with the fact that this is completely out of my control. I have to take it extremely seriously. I'm extremely dedicated, extremely committed to this process moving forward, and I want to go into this and show these teams who I am as a person and who I am in the football facility that not everybody gets to see."

Manziel worked out in front of 30 NFL teams, but the front-office decision-makers from the Cleveland Browns were not among those in attendance. As part of his maturation process, Manziel learned to only worry about those things in his control.

"I'm not disappointed," Manziel said of Cleveland's no-showing his pro day. "If they wanted to be here, they had the opportunity. I don't think anything of it. I didn't even know that was the case. I'm sure they have their own standard or whatever it may be, so I don't hold it against them. It is what it is.

"It's out of my control. I'll just go through it, like I said, and try to be as good as possible, go through this process with a smile on my face because you only get to do it once. At the same time, I'm in a position where I can play the game for a couple years, hopefully, a lot of years.

"In the grand scheme of things, it's a game. I come out here and play with a great group of guys, have had great teammates, great coaches. It's the greatest game on the face of the earth. I'm enjoying everything. At the end of the day, things are going to work out just the way they're supposed to, just the way it worked out that I was supposed to be here."

As Manziel prepares for the next step in his football journey, the NFL Draft, he does so as a more mature person, according to those who know him best.

"Those are questions that he answered last year," Texas A&M coach Kevin Sumlin said after Manziel's workout. "During the season, I don't think there were any issues. He wasn't on Twitter. He wasn't on a lot of different things. His ability to prepare is really, really good.

"You don't play at the level he plays and against the type of competition we play against and just roll out of bed on Saturday and run out there against Alabama. He prepares as well as anybody. He's a leader, and I think that shows with his teammates and how he performed for us on Saturday.

"I'm sure anybody that age that has made some mistakes or done some things that they'd like to have back. He's probably a little bit different because his every move was known. I saw a guy change dramatically in a matter of the two years I was around him, and I look for that change to continue."

It is because of the way Manziel works that led him to a better statistical season in 2013, when he completed 300 passes for 4,114 yards and 37 touchdowns against 13 interceptions. That is why Sumlin believes Manziel can succeed at the pro level.

"I think he can fit anywhere," Sumlin said. "If somebody asked me about systems and all kinds of stuff, I think (Seattle's) Russell (Wilson) kind of changed that. He played at Wisconsin in a two tight end, play-action, handoff system and he goes out in a West Coast offense.

"It's the ability to take your talents, know the offense, be able to be accurate and move your football team. I think he's got the ability to play in a bunch of different systems, not just because of his mobility, but as he displayed (Thursday), his accuracy."