Ask him?
Sometimes kids (and adults for that matter)... need a little coaxing into thinking about what they want to do with their lives (and then time to think about it).. but you may well be very surprised at his answers.
One thing I've done with kids in the past if have them write a short list of 3 "sets" of things.
1) Out there (like astronaut, trapeze, spy stuff)
2) Possible (local sports, arts, clubs)
3) Boring but might under the right circumstances.
Then I typically try and see how the "out there" list could be achieved. Spy stuff... for example... translates to gymnastics, languages, cyphers, security, politics, tactical reasoning, spatial reasoning, etc. All of which is super doable.
R