I didn't think as much about it at the time, but especially recently as I've felt particularly productive, the simple buckets have rung true for me.
His take was there was three things you needed to do to be happy, productive - and hence successful - as a Product Manager. Its a simplification, but I do think it's mostly true:
Ship s%#t: Product is mostly about deciding what to ship, and then working on shipping it.Fix s%#t: Stuff you (or others) ship is going to be wrong or broken. There's satisfaction in improving and fixing stuff. Start s%#t: The most fun is starting new projects - things you or others came up with.