In the book “This Gaming Life” autor Jim Rossignol’ attributes the following quote to Will Wright, the original designer of games like SimCity, The Sims and Spore:

When we do these computer models, those aren’t the real models; the real models are in the gamer’s head. The computer game is just a compiler for that mental model in the player.

We have this ability as humans to build these fairly elaborate models in our imaginations, and the process of play is the process of pushing against reality, building a model, refining a model by looking at the results of looking at interacting with things.

(via —Magical Nihilism)

 
Also take look at this interview with Will Wright on Spore, SimCity, and the Sims: