money

I was walking down the hallway at the university today, on my way to class and for a while actually feeling awake, and I heard someone ask someone else "If you had all the money in the world, what would you do with it?" and I thought to myself; if someone had all the money in the world, then no one else would have any money at all. Doesn't money work only if there is a mutual understanding and value of money and if no one, except one person, had money, wouldn't it loose all of its value?