Humans have an inherent need to justify spending resources on things. People want to know that the time, money, emotion, empathy, or any other personal resource they spent on something is not wasted, even when it is. A good example of this is our time and money investment in leisure activities. There are thousands of comics and baseball cards in circulation, but only a handful of them are worth more than the paper they're printed on. Only a handful of people care who has the world's highest score at pac-man or pinball. Some things can end up being somewhat worthwhile, such as being a professional Magic: The Gathering player, or a professional Starcraft player. These are, of course, few and far between. The ratio of grand master chess players to regular chess player is extremely small, just like not everyone can be Kobe Bryant or Tiger Woods.
What does this have to do with games? Well, in games that save your state, it starts becoming important. The entire genre of MMORPG is all based on ascribing value to something where there really inherently isn't any. I've never seen another specific genre of game take this to such an extreme, and I wanted to spend a bit of time analyzing it.
( Ok, so analyze already )