While on some level, it's sad that Jack lost that last good memory of his father, you're right when you say that he wasn't using it. And once it's gone, you don't know that it was ever there. You can't miss it. It's also unlikely that it's the only positive memory Jack has of his father.

Commenting to say that I really enjoy your reviews. They're always well thought-out and it feels like you always try to put a positive spin on things, which is a much needed break from a lot of the other analysis.