In that case, the student I worked with was about 8 mentally and emotionally. He was fascinated with NASA and often looked at its official website for souvenirs. He bought one of their badges to get sewn on his jacket. He talked about his trip to the space center and going on a vertical ride through the solar system.

If he had the brains and the money, I have no doubt he'd want to be an astronaut. His parents had other ideas of course considering his limited abilities.