I like to think that the time the weird longbearded wizard accused his parents of mistreating him worse than they mistreated Harry got him thinking.
I like to think that he went back to Smeltings and considered things. How Harry got his first cake that night on the island and how happy Harry was, and how upset Dudley had been at only getting 36 presents, and he can’t even remember what most of them were. How his parents adore him but they keep insulting things Dudley thinks are cool, like motorcycles, and he doesn’t want to be a manager and go golfing. How it sucks to be hungry, but it’s nice to appreciate food, and how food seems to taste better after a boxing workout than after five hours of TV. How being hit hard in the boxing ring hurts sometimes, and that’s from one person, his own size.
I like to think he goes to the library, and reads through the Dewey Decimal System, and finds books on parenting, and on child abuse, and on child psychology and development, and he laborously reads through them, and notices that reading and understanding get a little easier towards the end, and he checks out the book series attached to his favorite TV show and wishes his parents had gotten him to read back when he was a kid.
I like to think he writes a paper on toxic parenting for one of his classes, and it’s the first really good grade he ever gets.
I like to think that wherever they got sent to hide from Voldemort, there’s a different language spoken, and when Dudley goes to school and he’s the slow one, it’s presumed to be because he doesn’t speak the language, not because he’s slow or doesn’t try. And he remembers the payoff of effort, and talks to the other kids, slowly learns the language, slowly catches up, puts effort in, and his grades aren’t bad. He boxes, and he wins matches and he loses matches, and he never goes for the position of that kind of kid who bullies others at the slightest excuse. Just … doesn’t. Nobody expects it of him, here.
I like to think he doesn’t become a famous boxing champion, and he doesn’t go to a prestigious college or get a high-status job that lets him yell at people. He comes back with his parents and goes into London and finds a boxing gym, and he goes to a middle-of-the-road college and studies to become a boxing coach, and he uses the networking skills he picked up at Smeltings and the social skills he picked up abroad and he soon has a cadre of teenagers sparring in his ring, and it sort of filters through the grapevine at the local schools that if you’ve got a problem kid, either a spoiled rich kid headed for disaster or a desperate poor kid headed for prison, you send him Dudley Dursley’s way.
I like to think he turns out his fair share of stellar boxers, but to him that’s beside the point.