Do they really call California' The Golden State' because of its association with the Gold Rush of the 1800s, or is it because you almost need to be earning sacks full of real solid gold in order to afford to live there? The cost of just about everything in California is eye-wateringly expensive. You're looking a $20K a year just in housing costs, and then the best part of $10K on top of that for food.
Admittedly, the cost of all this is somewhat skewed by a couple of important facts. For one, Los Angeles is in California, and so the high prices there drag up the state average by quite a margin. Secondly, this is where Hollywood is based. Hollywood dreams don't come cheaply, and neither does being in or around that particular industry. Then there's Disneyland to think about as well. Anywhere there's big money, the cost of living goes up. Rich people need something to spend their salary on!