No problem :-) Everybody learns by finding things out or people looking over their shoulders saying "hey, do you see this neat feature over here?" :-)

The "blame" thing is a kind of joke of course, one that was apparently funny enough to be used in multiple version control systems. Subversion (another geeky joke!) has it, Git has it, and Mercurial, but CVS and Monotone don't. I'm not familiar enough with any others to say anything about those.