Computers these days are fast. Really, really fast. They can store and process complex operations on huge numbers of variables at speeds which, frankly, are a little alarming when you occasionally watch videos of bipedal robots opening doors. There’s something a teeny bit Jurassic Park about it.
Malign portents aside, there’s a huge amount a computer can do once you’ve written a set of parameters and rules for it to follow. While we may one day be able to get computers to program themselves, for now we’re stuck doing it and that means that to bring a game to life you need to write hundreds of individual scripts some of which amount to thousands of lines of code and then surround them with thousands of multi-media assets.
There aren’t many things which are more rewarding, stimulating or difficult.