As someone who's been in university, either as a student or a reseacher for a little over 40 years now, I'm all for learning for learning's sake. Especially as many of the seminal discoveries in science, for example, were made by people looking for something else. It is, as they say, the journey not the destination that's important. And if you need a practical reason, there is evidence that continuing to exercise your brain reduces your chances of developing dementia as you age.