Have you ever considered sorting out that mess? I bet you have, but you really need a PC to do it. Hundreds of contacts, dozens of message conversations, a thousand pictures (vaguely equivalent of one million words) and a collection of apps which if they were to be random objects, you would most definitely be called a hoarder. Imagine the thick data jungle that your phone must be holding. Usually at those flash memory dinner parties that it goes off to while you're sleeping. So your SIM card is older than mother Earth itself and your SD memory card has seen more phone entrails than it would be happy to admit.
