key problem

If anyone really knows me, they'll know that I have about a million and one key-rings with various objects dangling from them. I have accumulated an unprecedented number of them through the whole of my lilfe, and still they keep on coming. People give them to me as gifts, I get them free with the clothes I buy and my sister wins them in lucky dips. However, I needs ask one question: if I own only 4 keys (all of which I carry one the same key-ring) why do I need so many key-rings?