Ok. California is a community property state, which means anything you own before marriage, and bring into marriage, anything you inherit during marriage, and anything you get as a gift during marriage, will be your separate property. During divorce or separation, this portion is always yours. That includes anything, from stock to cash, to a house. Who told you that you would split 50-50 is WRONG.
Anything you acquire during marriage, like wage, salary, lottery, would be community property and you do have to share 50-50.
That being said, even things acquired during marriage can be separate property. That is through transmutation, which has certain legal requirements, through which you can legally allocate a property to one spouse or the other as separate property. As said before, you take 100% of separate property during divorce or separation.
That is a nutshell of community property system which is valid in 9 states. If you need further discussion send me a qqh with contact information. I'll be glad to discuss these terms with you.