This thread mentions a few helpful sites that can assist you in visualizing and understanding regular expressions.
I love regex and wish I had learned it 15 years earlier than I did. It would've saved my poor hands hundreds of thousands of key presses and myself hundreds if not thousands of hours of manual work. I always had the nagging feeling at the back of my mind "there's a pattern, there must be an easier way to do this".
Well, there was.