I bought this wallet because of how slim it is.  It is literally a sheet of the fancy paper folded up to form a wallet.  So it adds very little extra girth to your pocket.
I've never actually used any of the "knowledge" printed on it, but it might come in handy one day.
Only two complaints: due to it being a folded sheet of paper, sometimes the cards get hung up on one of the folds inside the wallet.  Also, it is pretty slick since it's a coated-type of fiber.  This makes the plastic cards slide around in it.  I'm always worried a card is going to slip out of it.  This has never happened, but it's a concern.  But that might just be my OCD.
I have no doubt that this will probably last forever!