These data are unequivocal: we are building a civilization of ignorance. - Sam Harris

The human mind does, in fact, contain vast expanses that few of us ever discover.

Britain has become a net exporter of Islamism and jihadism. My former Islamist group didn’t exist in Pakistan until we exported it from Britain.

You are not in control of your mind — because you, as a conscious agent, are only part of your mind, living at the mercy of other parts.15 You can do what you decide to do — but you cannot decide what you will decide to do. Of course, you can create a framework in which certain decisions are more likely than others — you can, for instance, purge your house of all sweets, making it very unlikely that you will eat dessert later in the evening — but you cannot know why you were able to submit to such a framework today when you weren’t yesterday.
So it’s not that willpower isn’t important or that it is destined to be undermined by biology. Willpower is itself a biological phenomenon. You can change your life, and yourself, through effort and discipline — but you have whatever capacity for effort and discipline you have in this moment, and not a scintilla more (or less). You are either lucky in this department or you aren’t — and you cannot make your own luck.