By Oher's senior year, the grueling work was beginning to pay off.
"He'd come in and slap his test down and put mine right next to it," said Collins Tuohy. "'I made a better grade than her. Hey, you all look at this. I made a better than her today.' You know, I'm like, 'Cut me some slack, you know, like really.'"
Life was taking a fantastic turn for Michael Oher. Not only was he making an academic comeback, but his football career was taking off wildly. College scholarship offers began pouring in.
"The truth is, we never completely thought that he could qualify [for college], 'cause he had so far to go," said Sean Sr. "There is no way he should have."
But the moment his family never thought possible finally arrived: Oher graduated from high school.
"The Blind Side" depicts the graduation ceremony.
"I have seen the movie seven times," said Leigh Anne Tuohy. "I cry every time I see that part."
Oher said graduating felt great.
"It was unbelievable just to, you know, walk across the stage and shake the principal's hand. I was the first one ... out of anybody that I ever knew to, you know, graduate. ... It was ... a great experience."
With diploma in hand, the kid from North Memphis was now ready for college. Of all the choices, he went with The University of Mississippi -- Ole Miss.
"Ole Miss was right down the road, and I figured it would be easier for my family, you know, my friends to get down to Oxford to come see me play," Oher said.
Ole Miss was also Sean and Leigh Anne's alma mater -- and where Collins would be headed as well. On the football field, Oher was a starter from day one, becoming an All-American and left tackle, with Collins Tuohy cheering on the sidelines.
She said it was fun -- and sometimes a big help -- to have her brother with her at school.
"My sophomore year I had to move into the sorority house at Christmas," she said. "But my roommate and I had acquired a lot of stuff, a refrigerator and a microwave, a TV. And we had to do it in like five hours. And I just had a meltdown -- I mean, literally called him in hysterics. And he goes, 'Just get off the phone. Give me five minutes, come downstairs.' And he had brought him and the entire offensive line ... and they moved us out in five minutes. Not kidding, the whole dorm room, all the way over to the sorority house. I'll never forget it. I opened the door to the sorority house and the house all was like, 'Where did you find all these boys?'"
After playing just three years for Ole Miss, Michael Oher became eligible for the NFL draft.
Watch "The Blind Side: The True Story Behind the Movie" on a special edition of "20/20," Tuesday, Dec. 29, at 10 p.m. ET