In college, he walked on at both Texas Tech and Oklahoma and won the starting job. He won the Heisman Trophy with the Sooners and became the first player in modern NFL history to go from walk-on to No. 1 overall pick.
So being firmly entrenched as the Browns' No. 2 quarterback behind Tyrod Taylor coming out of the preseason and knowing it's going to remain that way through training camp is a tough pill to swallow.
"It's human nature. Yeah, you want to play but I wasn't brought here to just start,'' he said Wednesday after the last practice of minicamp. "I was brought here to help turn this thing around and whatever my role is that's what I need to do, whether that's playing scout team or being the best backup possible or playing. So for me I'm not worried about that.''
Mayfield admitted last week that his progress hasn't been fast enough despite being bumped up to the second team, and that didn't change throughout minicamp.
"I want to have it all figured out but that's just not how it works, so yeah, it's about realizing we're going to have to take baby steps right now to get to where I want to go,'' he said. "You don't build a great castle just all at once. You gotta build it block by block and so for me, that's how I need to handle it."
Fortunately, that phonebook-sized playbook, which looked at first like it was written in hieroglyphics, is starting to make sense and it's translating to better practices.
"The game is starting to slow down a little bit, starting to recognize a little bit more, being more tuned in with my protections and that just comes with continuing to learn the offense, learn our guys and ... know where to go with the ball,'' he said.
Mayfield's first two months on the job haven't been as he might have expected. In the first OTA open to the media, he threw three interceptions (two off receivers' hands) and two more that were dropped.
"It's definitely had more of a learning curve," he said. "There's been some bumps in the road which was expected, but right now I'm just trying to find a consistency.''
Mayfield's progress is sufficient so far for Jackson.
"The biggest message I send (into the break) with Baker is keep working,'' he said. "That's who he is first and foremost. The day he walked out here, there was no question about the arm talent, his ability to ad-lib plays and throw the ball down the field.
"It was being under center, the terminology, how fast is he going to be able to say the play in the huddle and communicate all of this information to the whole offensive football team, and I think he's handled that well.''
Jackson must balance making Mayfield wait with not letting him get discouraged.
"He's one of those guys that's always itching to be the best at what he does and you like a guy like that,'' he said. "He's going to keep improving; from day one to where he is now I've seen a lot of improvement."
One thing he's never questioned is Mayfield's arm talent and accuracy.
"He can throw a football, there's no question about that,'' said Jackson. "He can really throw a football whether it's short, long, tight spots, all of that."
The mental side of the game is where Mayfield hopes to make the biggest jump during the five-week break before camp.
"That's the biggest difference from college to NFL,'' he said. "Everybody's so talented at this level, the difference is knowing the game - knowing where to go with the ball in my position, knowing how to execute your job to the highest level. In college, you could just get by playing ball."
Fortunately for Mayfield, he's got two great teachers in Taylor and Drew Stanton.
"He has a great mindset,'' said Stanton. "He's asking questions that are relevant. He's engaged and he's doing it the right way. He has all those tools that you're excited about. Obviously, there's a reason why he was drafted No. 1 overall."
Stanton said Mayfield's questions are "next-level thinking, and you can see his football knowledge is very high."
In Stanton, Mayfield has a willing mentor. Taylor's job is to run the offense.
"I'm here to be his advocate, to help him speed up that learning curve for him and do everything I can to try and help him get prepared to play,'' said Stanton.
"If you don't get along with Drew, then something's wrong with you,'' said Mayfield. "He's a great guy. He keeps it light and fun. But also he's so knowledgeable. Every once in a while, even if I'm not asking a question, he'll slide little tips and advice. He helps me out a lot.''
From Taylor, he picks up things such as footwork.
"Being not the biggest guys, he makes it work with his feet,'' said Mayfield. "He's always in an athletic stance. He's balanced, able to get the ball out quickly, but he's so detailed in that he's always in a position to throw or escape the pocket. He's very good at it."
Fortunately for Mayfield, he's getting acclimated to the city and his teammates. He's made close friends with guys like Josh Gordon, and he's attended Cavs playoffs games and felt the passion in The Land.
"I love it here,'' he said. "First of all, the Haslam family makes it -- no other place is like this from what I've heard. In all of my visits, I also noticed that as well. They're here every day.
"Cleveland as a whole is a great sports town. People love the Browns here. People told me beforehand of being here but actually starting to settle in you notice it more and more. It's a great spot to be."
Mayfield now enters the pre-training camp "break" knowing there's plenty of work still to do.
"Obviously, it's a huge 5, 5 1/2 weeks for me,'' he said. "Continuing to learn and work out, stay in shape. I'm going to plan it out where I can study certain things, week by week. There's a certain time and place where you have to step away from it a little bit, hang out with family for maybe a week and then get it back.''
When he returns in late July, the No. 1 pick will get back down to figuring out how to be No. 2.