Revitalizing Islamic Education for Children

The Aqeedah syllabus in some high schools where I have taught or studied is no different from that of the primary levels. Nothing interesting, new or even important is taught which the students have not already learned. When the syllabus is too simple and students feel they already know a subject, their minds switch off and they lose interest. Islam is so vast and so deep, why is it that we underestimate our children and teenagers and limit their access to knowledge to only the basics?