Specifically "Canola Fields" by James McMurtry. I feel like the older I get, the more this sort of songwriting resonates. It's impossible to escape. Even if you're not a dad yet, the dad rock finds you. Be warned.
Anyway, one of the lines is so simple, yet poignant, and, to me, that's the true hallmark of good songwriting. The line: "cashing in on a thirty year crush, you can't be young and do that". It reorients aging in a way that really struck me. Smashing together the childish and the mature and flipping the usual loss/gain calculus. Showing that just as there are certain things unrecoverable to the old (that humming freshness of youth!), there are also things that are incomprehensible to the young. It's a dialectic, and romance and beauty come in many forms.