Learning a distributed version control system is kind of a revelation. If you're like me you've probably gone through the following progression. You started off with SourceSafe. You thought, wow, how did we ever get things done without version control?
Sometime after that you switched to cvs. If you were like me you probably thought. Wow, I can't believe we ever put up with all those locks and only allowing a single person to edit a file at once. How stupid was that?
A few years later you might have switched to subversion or svn. At the time I remember thinking. Wow, how did we ever live without atomic commits?