My mate at uni told me today about a hidden track on the Bloc Party album, which I never knew about

I've had this album since it come out (8 months or so) and I didn't have a clue it was on there at all, so I don't know how I've missed this up until now

Am I thick?! If you press play on track one, then hold down back track (rewind, whatever) it goes back to another song

How does this not show on iTunes/Media Player/whatever?

Also, any other hidden tracks (at the start of the album) that I've foolishly been missing out on?