this is a book I've been charged library fines for. i found it impossible to read straight through, I've been dipping in, reading it in chunks as the whole starts to make sense. That's why it's so brilliant - de Certeau has watched us in our everyday lives and unravelled the way we (consciously or not) play along with or undermine the games we have to play in order to live in cities.
He's seen us at work, blagging company time and resources for our own ends, and he's noticed and explains how we behave towards each other on the tube. He's been sitting in crowds and on the train, and he's been walking the streets. He's breaking down without breaking out of the spaces we live in.
This text can change the way you perceive what surrounds you. Wherever you are, it transforms people-watching into something strange and different, because it's suddenly all structures and sequences. It's quite disorientating (remember the story about when the centipede was asked how it managed to walk, and it promply forgot) but it offers so much as compensation. I'll read this in a week and think I've got it all wrong, but that's the beauty of it.