There are about 50 kinds of history teachers. He may never be able to be a college professor of history, but ESPECIALLY if he has a specific disorder, he could be an INVALUABLE history teacher working in a program specific to those with his own disorder.
The fact of the matter is: NONE of us can just "be anything we want to be". I think it's a travesty that we tell our kids that.
What we CAN do, is do whatever we LOVE... with hardwork, imagination, and luck or patience (luck primarily has to do with how QUICKLY we get to do what we love, and in what capacity).
I "want" to do maybe 50 things I just plain and simple can't. BUT, anything I really love enough to put in the time, work, and creativity... I can certainly do.
Take the childhood dream of astronaut or president or rock star or pro sports player that many kids have. Lets face it, about 6 people a year get to be astronauts, and 1 person every 4-8 years gets to be president. BUT 10's of thousands and 100's of thousands and even millions of people:
- Work in space related fields : from astronauts, to physicists, to astronomers, to teachers, to computers, to cartographers, to mission control, to engineers, to docents, to artists, to, to, to... there are MAYBE 500 career paths I can think of off the top of my head that have to do with outer space. And at least 100 that have to do with *actually* flying... if their passion for space is actually a passion for flight.
- Work in POLITICS... from local, state, national, party... to things like the State Deptartment (diplomatic, economic, managerial, justice)... and then you have all of the 3 branches of govt. aspect of politics : Judicial, Executive, Legislative... then you have lobbyists, journalists, etc.
- Work in MUSIC... players, writers, stage hands, crew, roadies, security, producers, agents, studio engineers, mastering, scouting, exec, promotion, venue ownership, designers, teachers, journalism, photography, etc.
- Work in SPORTS... aside from athletes you've got coaches, trainers, journalism, artists, equipment, agents, grounds crew, etc.
These are just a smattering. And in each and every single one of these career paths there are also LEVELS. Okay, you're not coaching an olympian or the cowboys... there are also peewee leagues, school teams in E, M, HS, community leagues, college, and THEN the pros. Music teachers can be at Juliard or a preschool. The astronomy prof may be the *worst* person in the world to inspire 6 year olds, the killer teacher for 6 year olds might be *terrible* as a tech charting star movements. There are just so many avenues, and no one is good at them all. We all have a range of niches that we would both excel AND be happy doing.
Your nephew just wants to be a history TEACHER. He's got soooo many different ways that he can do that. He just needs to find the ways that would work for HIM. Saying "no, you can't, give it up" is an even bigger travesty than saying he can do whatever he wants. He just needs to find and avenue that works for him, where he'll shine and be happy.