Wife & Whether to Helmet or not to Helmet

My wife and I have an agreement that I may cycle as much as I wish provided
that I recover fully from any injuries. In other words, no brain damage or
permanent disablity. In the event that such injuries are sustained, I am
instructed that I should die.

So, my questions is... in order to live up (har har) to my end of the
agreement, would I do better to wear a helmet or go hatless?