That's fair, but a hiring manager might be more easily able to see this overlap if you have some recent side projects.

And again, I'm not even the type to code for fun at home (at least not since my first two years out of college). My significant other never codes for fun but is probably one of the most talented programmers I know. I'm just stating some reasons why one might ask this as an interviewer.

The absence of side projects doesn't indicate a lack of passion but the opposite of this is mostly true.

Exactly! I used to be a climate scientist, and wrote open source libraries on my free time. I now work as a software engineer, and I love my job. But on my free time I now make music.