Can you give me ONE example?
Sure, checkout Chapter 2 (http://mitpress.mit.edu/sicp/full-text/book/book-Z-H-13.html...). It shows how you can define data structures such as lists or trees from a simple pair concept and then define generic operations over them, such as map.
For me that's been one of the great things about the book, it shows how you can build higher and higher levels of abstraction from relatively simple structures.
I'm finding that seeing concepts I take for granted when I'm programming being built up from first principles changes the way I think about the languages I use.
I'm not sure it's made me a better programmer, but it has given me a better understanding of why programming languages are the way they are.