I started hearing about this CSS preprocessor stuff a couple of years ago. The concept intrigued me: Use special, supercharged CSS files that could contain variables, functions, "mixins", and other features. After development, these special files would then be compiled into regular CSS files that all web browsers could understand.
To my peril, I stayed away from CSS preprocessors until recently. "Why should I add another layer of complexity to my development workflow?" I thought. "I know what I'm doing with CSS. If it's not broken, don't fix it."