You know you're fixed gear crazy when...

...when you look at every single bike on the road, every single bloody one, and are able to see if there is a rear derailleur faster than you would have ever thought possible.

+1. Beautiful. Still nodding in agreement.

When you get the distinct feeling that your friends, colleagues etc are deliberately avoiding the subject of bikes, lest they have to put up with your fixed gear repertoire yet again.

And when you lump all other cyclists together with m*torists as 'just sheeple, really'.