What is wrong with adults? Why do we have to make an immediate assumption about what children will do 'when they grow up'? Why can't we just let them 'be kids'.
Stroke a dog and you'll grow up 'to be a vet'
Show an interest in lego and you're an engineer in the making
Ask to stir the gravy = "next Jamie Oliver"
Pick up a leaf = botanist or better still 'Attenborough'
Skip = gold winning olympic gymnast
Run - gold winning sprinter
Observation on culture or opinion on right or wrong = next prime minister
Seriously, is this necessary, just look at their faces when you say this, they think we're all mental.