Since it's a quotation from a writer this made me very happy. I also let it percolate in my head all afternoon, and eventually distilled it to this: It's never too late to write what you might have been writing.
It's easy to get discouraged and give up on a story that you think you can't write, or you're convinced you can't sell, or for whatever reason just scares the bejesus out of you. The vision is there, the story is waiting, and suddenly your spine turns into pudding.
I think most of the stories we don't write turn into vague regrets, but a few become ghosts that follow us and haunt us. I try to write mine into short stories whenever I can, just to exorcise the little demons, but there are a couple that won't work as anything but novel-length works. With my schedule I already have to be very selective about what I write; I can't afford to waste my energy on a project that worries me more than it excites me (and even as I write that, I feel like I'm making excuses. If I really wanted to, I could make the time.)
I'd say of all the might-have-written novels in my head, there are four that someday I would like to get over my fear and get them down on the page. Even if the only person who ever reads them is me. I don't know if I'm ready to say I'm planning to write them; maybe they need to haunt me a bit more.
How do you handle your might-have-written stories? Let us know in comments.