The people you met probably went through the 'classe preparatoire aux grandes écoles' https://en.m.wikipedia.org/wiki/Classe_pr%C3%A9paratoire_aux_grandes_%C3%

The people you met probably went through the 'classe preparatoire aux grandes écoles' https://en.m.wikipedia.org/wiki/Classe_pr%C3%A9paratoire_aux_grandes_%C3%A9coles https://en.m.wikipedia.org/wiki/Classe_pr%C3%A9paratoire_aux... It's brutally efficient at selecting the best math students (including the ones who actually want to study engineering, since the entrance exams are about maths and physics ) , and the sheer amount of work you put in two years is absolutely staggering. It's obviously not perfect, and people regularly talk about getting rid of this system, but it works well for the students who survive.