If we’re doing the almost-infinite amounts of wallets for the players of the game, we’ll need an equally big set of keys for those wallets.
Well, since this is all digital, we can decide that a key will be a very specific and long random-looking sequence of letters and numbers. So long and random that if you try to guess a specific key that holds a lot of moneros, it would be the same as picking the right grain of sand from all beaches in the world combined. That would require a lot of luck. So if we give a monero user a key, nobody else could just guess his key and use his moneros as their own.
Math to the rescue! Using math, we can use a set that contains 115,792,089,237,316,195,423,570,985,008,687,907,853,269,984,665,640,564,039,457,584,007,913,129,639,936 choices for keys. Actually, forget the grains of sands, it’s calculated that the number of atoms in the observable universe is something like this: 102,468,180,827,345,678,901. So look at our pool of possible keys with awe and pride.
Every key is like that wallet’s DNA. Like a seed that grows a tree with many branches on it. Branches with endless accounts and addresses. Following that idea, we’d only need to save that seed and every time we plant it, the same tree with the same branches would grow. It’s like writing down the DNA of identical twins.
Every user now just has to store those keys safely, and be able to get one of those grains at will.