When Bruce took him in, Jason was hesitant to go back to school.
He knows he's smart, being placed into advanced reading in fifth grade does that to a person. But after spending the better part of his childhood caring for a mother so sick he starts to skip school... things like Lord of the Flies become obsolete.
Then his mother dies, and he drops school completely to fully focus on his survival. He tried to go back once, but the office tried to sick social services on him.
So, when he's not scrounging around for something to help aid his survival, he's at the Gotham Public Library to fill out his education as he sees fit. Most of it is classical reading and occasional fiction. He does learn a lot about cars, though.
Batman takes him home, and despite no longer being completely unsure of where his next meal comes from, he spends most of his day trying to reinvent a schedule that doesn't make him go crazy. Robin can only take up so much time before even that makes him go mad. So, Bruce suggests he go back to school.
He's supposed to be a sophomore. At least, that's what his age says, and he's technically tested into 11th Grade Writing. The school barely lets him join halfway through the year as a freshman due to his lack of formal education and math scores.
Despite a huge ego blow and definite self-confidence issues, he actually really enjoys school. His favorite teacher is actually an art teacher, because she's nice and grades on effort, not skill. He's even made a few tentative friends. Even if he gets sent to the office for beating the crap out of a kid picking on some middle-schooler for being considered to skip another grade, that's his business, not the teachers'. Besides, he knows he's smart, and that's what matters.
He spends the next couple months after he wakes up a husk of who he is, barely able to string thoughts coherent enough to get himself fed and find a place to sleep. After that, he spends his days in some old compound surrounded by personal tutors and taught by what might be the oldest family alive.
Then, Talia tells him about Batman's new Robin, and he feels like a used car part that failed to make the car run again to eventually be replaced by a new car entirely. He starts researching as soon as he gets out of the compound.
It's weird, cause this kid used to be in his math class and barely spoke two words to him despite sitting right next to him. Now he's jumping around wearing Jason's old colors.
A kid, who was healthier when Batman picked him up. A kid, whose parents were still alive, who never had to want growing up because he already had everything ready at his beck and call. A kid, who despite skipping school to galivant around with Bruce, is still three years ahead the academic norm.
Tim got everything he wanted and more, and Jason was held back.
Isn't that just the kicker?