The author has been puzzled since age 9 about the contradiction between being made of predictable matter and feeling free to choose.
An initial incorrect answer is that you can do what you want but cannot want what you want; however, people can change their wants (e.g., addicts).
The corrected answer adds layers: you cannot want to want what you want, and with each added 'want to,' change becomes rarer, leading to an ultimate want you don't control.
This can be expressed using a regular expression or higher-order desires: there is some n such that you don't control your nth-order desires.
Randomness in matter does not significantly affect the problem, as it still undermines free will.