Because it was my first startup and despite days of research into how options work, I clearly still didn't understand it all. So I trusted his answer. I had no previous experience or knowledge that would have led me to believe that they wouldn't follow through with the promise to grant additional options over time.
Your company does not 'promise' you compensation - they have a contract for that.
If you were to have some kind of special 'non dilution' clause in your equity position (which by the way, no founder would reasonably agree to), then you should have it in writing.
But it's moot. One or both of you was obviously struggling with how all of that worked, because giving employees anti-ratcheting clauses is not something that should really be done. In fact, it should be avoided if at all possible even with investors.
