There's a simple explanation for this which doesn't require stereotyping all Saudis as lazy: the students you met, who studied abroad, were from wealthy families who could afford to send their children internationally. Why work hard when you can have a good time for four years before rolling home to a cush job? It's the same with the rich in the USA. Unless the kids find a specific passion they mostly just fuck around. I personally know several rich kids from American families who do this, and float around between half-assed jobs for their 20s and 30s.