One thing no one told me:

When you cofound a company, its not the equity percent, but who is in control that matters. If you have 40%, and they get 60%, but legally or otherwise (you are the face of the company), then you have control and the 40% is worth more than the 60.

If you leave early after cofounding a company, there is no saying what happens to you shares, and likely they will be diluted to almost nothing

Its all about control.

If you are an employee, either go for a company thats a few years from IPO, a generational startup, or consider the equity worth 0.