Who am I?

My computer is constantly asking me who I am. In fact, every time I go someplace new in cyberworld they ask who I am. My name does not seem to be sufficient- I must have a Username and a Password that needs to be changed on a regular basis. My Username must reflect who I am but not actually reveal my true identity. My Password must be something that I can remember (HA!) but not something that someone else might be able to figure out. All of this because of security.
There seems to be a hot market for stolen names these days. I don't understand this. Most people are given three or more when they are born. They often pick up several others as they go through school, get married, join the military or enter the work force. Just how many names does one person need? And what happens to them? Do they wear out? Do they break? Are they lost, perhaps inadvertently left behind when one is shopping or on vacation?
When I was a child I would have gladly given someone my name. I wore it like a pair of shoes that were too big but had been laced up so tight that the middle pinched while the heel rubbed up and down creating a blister. It just didn't seem to fit. Funny thing about growing up. Lots of things start to work right without you even realizing it. One day I woke up and realized that my name was just right for me. It fit me perfectly. And even more surprising, each year it seems more and more tailor made just for me.
So now, when Cyberworld asks me to rename myself, it is a real challenge.