You're sorely wrong. Divorces in several states, California included, are like mutually assured destruction with one side having twice the firepower, and everything about a relationship can change in a divorce.

To OP: you don't have to hide your assets in offshore accounts, you can talk to an estate planner and look into setting up a trust (google domestic asset protection trust) and make yourself the sole beneficiary. You would no longer "own" the money and it's protected in a divorce.

Also prenups are typically worthless in the madness that is family court. Never ever ever rely on one.