For me, I think the most important reason for working with lisp and its variants is that it allows you to (and you should) code from the middle.
When I first started programming, and for a long while, I'd think top down. What do I got? Then, how can I iterate through that to do the operations I want and then build up what I need?
With lisp, the ability to reuse code in closures is so easy, you can afford to think a different way. What are the most basic, clean and simple, operations I need to do? (not necessarily in order I need to do them) This includes conversion, summing results, iterating through a structure, etc.
After writing functions for those, you can quite easily plug them all together without much thought.
You end up with code that is non-redundant, clear, reusable, easy to debug, and flexible.
When I first started programming, and for a long while, I'd think top down. What do I got? Then, how can I iterate through that to do the operations I want and then build up what I need?
With lisp, the ability to reuse code in closures is so easy, you can afford to think a different way. What are the most basic, clean and simple, operations I need to do? (not necessarily in order I need to do them) This includes conversion, summing results, iterating through a structure, etc.
After writing functions for those, you can quite easily plug them all together without much thought.
You end up with code that is non-redundant, clear, reusable, easy to debug, and flexible.