Regular expressions are awesome!
I think regular expressions is a topic that gets equal love and hate from programmers. We love it when it works, and when it doesn't it makes us want to pull out our hair. (Perhaps, bald programmers are the most experienced Regex users? ;) )
If used right, it is an awesome tool to improve your Find/Replace superpower! I have realised that I use it more often than before, especially when refactoring code where I need to make adjustments in multiple places.