we have driver's licences, college id, non-drivers id usually people dont carry around a passport.
out of curiosity Speelgoedmannetje why wouldnt you want to carry id. i see no benefit to not having id and lots of drawbacks. people here in the states carry id for proof of license to drive, proof of age to buy alcohol and smokes, and for id in certain finacial transactions.
its not like you have it clipped to your lapel for all to see.
most people dont like showing id because they have terrible photos on them (ive used the same photo for 12 yrs (glasses and slightly thinning hairline are only differences))