But this was California where even signed legitimate non-compete contracts are mostly not enforceable, so I dont see that being an issue either.Experience and expertise gained while working for a company is yours to keep and yours to use at will. The company pays you for what you create for them and they keep just that. They can use your skills and knowledge to their benefit for as long as you work for them but they don't get to keep that after you quit.
They can prevent you from working for another (competing) company provided you sign a non-compete clause in your contract. And then there are laws concerning confidential information and intellectual property, which you must not "steal".