In my experience, having fun while learning really takes away from learning. It slows down and hinders progress and becomes obnoxious after a while. The target

In my experience, having fun while learning really takes away from learning. It slows down and hinders progress and becomes obnoxious after a while. The target of comprehensive school and upper secondary is to teach people as much about different things as possible, have them learn social interaction and a small amount of how to learn and how to adapt information. They will likely not learn as much and as varied information ever again. The target of a university education is to have people learn how to learn, do research and apply that information, and drill into a single field and learn about that field and make progress in that field. Mixing "fun" into this is counter productive for the most part.