When you're discussing something geeky very intensely.
When you know a lot of
information about something unusual, usually
nerdy, and express it with great
enthusiasm.
Bruce: Batman never killed his villains until Robin died, which is the only reason why
people began to call him 'The Dark Knight'. And in the series 'The Dark Knight Returns', Robin was a
girl after Jason died.
Wayne:
Dude, relax. I only said I was excited for The Dark Knight.
Bruce: Sorry, I was nerding out for a minute there.