Part of the reason for gullibility at that age is no incentive to work really hard in school and trying to understand how adult life works. Grades instead of ranks, no fear of falling into poverty or survival mode (as would happen in a poorer country)
There is no reward for 'think and proceed'. There is reward for 'go with the flow' and that is temporary respite, not having to struggle, having fun etc.
At a systemic level, kids have to be encouraged to compete and become better AND demand better from others to be able to succeed.
I used to think I'd become a writer and write a book like Harry potter. At age 10, this naivety is cute. At 18, that literally is money (and possibly future life).
Schooling really needs a revamp.