Why learn anything not immediately useful ?

If you keep your natural curiosity alive and pursue your natural curiosity you will find very little knowledge irrelevant. Also I like the concept of Cultural Literacy the glue that holds this Society together. A compulsive browser in public libraries I love the experience of serendipity. The human brain loves those Eureka moments when it makes connections. Enjoying the world's great literature is not a matter of stuffing your head with facts . The human soul is inexhaustible. And so is the human capacity for empathy. Not being a professional scientist I never use the algebra geometry trigonometry and calculus I learned in high school and college. But it is no small thing to have some basic knowledge of how our universe works. Holy curiosity Einstein called it.