Serious answer:

I like how a colleague once put it.

There are two rather different types of mental fun, even though we use the same word "fun" for both.

There is the fun that comes from being heavily involved in something challenging, such as the fun that comes from competing with your best friend at raquetball, mastering a new level on a favorite video game, or learning the nuances of a theory of physics or a philosophical idea.

The critical thing about that kind of fun is that it must be challenging but not so difficult that a person feels helpless or lost.

There is the fun that comes from being relaxed and given a chance to escape from stress, such as the fun that comes from chatting about nothing at all with your best friend, idling away an hour or so at a video game you're already pretty good at, or watching a film with plenty of excitement but no demands on your intelligence.

Human beings need both types of fun. If we have too little challenge, we go mad with boredom. If we have too much challenge, we need a chance to escape for a while. And if we encounter a challenge that is beyond what we are ready for yet, we experience frustration and disgust.

When education provides a challenge that we feel up to, we find it fun. That's why most students love the classes that push them but push them within their capacities.

However, when education provides a challenge that seems meaningless or beyond us -- or worse, presents a challenge that seems boring -- we feel frustrated and irate.

Thanks to such idiotic policies as "No Child Left Behind", more and more public schools focus on mindless rote learning and obedient regurgitation of "correct" answers instead of challenging students to think and explore and feel. Why? Because even a trained rodent can learn to pass tests of rote learning, whereas only students who make an effort can do well when challenged and given a chance to explore and question.

Education is now controlled by those helicopter and steamroller parents who try to overprotect their children from all challenges; by those lazy but very loud parents who want their children off earning money for them as soon as possible and care only about diplomas, not about learning; and by those parents who don't want their children to learn how to challenge anything because they want their children to obey without question and ignore science or any other body of learning that might acknowledge evolution or global warming or the history of racism in this country.

So, education can and should be the challenging sort of fun, but it has been warped by those parents and politicians who see no value in any education except for the way it increases obedience and job security.