I think every programmer should have an understanding of what Regular Expressions are, how they can be used, and where to find a cheat sheet or reference (like

I think every programmer should have an understanding of what Regular Expressions are, how they can be used, and where to find a cheat sheet or reference (like www.regular-expressions.info). It helps to know the basic syntax by memory, but you can just as easily look it up if you understand how they work.