I have the power to control my thoughts.

Nobody chooses which thoughts arrive. They come the way a forgotten name comes, unrequested, at an angle, four hours after it would have been any use.

The power sits further down the chain. Not at arrival, but in the thirty seconds afterwards, where you either take the thing up and start furnishing it or you do not.

It is a smaller lever than you might want and a more reliable one. You cannot stop a thought forming. You can decline to build the rest of the afternoon on it.

Most days that is enough. The thoughts you never fed are the ones you cannot remember having.