My first exposure to Scheme (apart from education) was when I worked as a C++ developper. I was forced to make templates for expressing "functions as values" ideas I often had, that was not satisfying for me, as that language seemed to discourage me from doing that. I was striked by the beauty of how Lisp solved the same problem. Until that time I decided to know more about this language. Lexical scoping, absence of "funcall" (how odd this is, isn't it ?) and minimal design leads me to Scheme.
As Eric Raymond said in his "How to become a hacker essay": "LISP is worth learning for a different reason — the profound enlightenment experience you will have when you finally get it. That experience will make you a better programmer for the rest of your days, even if you never actually use LISP itself a lot." That's so true that I really recommend people learning Scheme.
Now I use it daily for 10 years and I am always glad with it. I am very grateful to participate in the Scheme Working Groups and wish the new coming R7RS to be even better for real-world applications.