I have a mentally and physically disabled adopted brother. He's about 25 years old. He gets 100% DI. He's a victim of fetal alcohol and drug syndrome. His biological brother is even worse off and is institutionalized.
He can work, sort of, as an apprentice automotive mechanic level or other lower tech menial job; but he will never be able to go beyond that. Assuming he even had the brains to manage his money, he might even make and save enough money to pay for a room and board; but not likely.