If I had to guess it went something like the OP's wife wanted a tool like this, the OP built the tool and made it to her needs but also public so that others could also have the same benefit. He's a HN user hence the Show HN and since it was an itch he scratched for his wife he put that in the title.

Not that complicated really. It could have been more clear with something like "A meal planner I made for my wife", but hey.