There are lots of writers who, very famously, get all doom and gloom about the whole proceeding and do their best to discourage people who want to write. They're like, "Oh, if you can do anything other than this, then you should!"
I am not like that. When people tell me they have an idea for a novel or that they've always meant to write one or that they're going to write novels after they retire, I say, "Yeah, that's great. You should do that."
Because, first of all, some people are naturally good at writing. They've read lots of books. They've thought about books. Or maybe they've written in their journal. Or they've told lots of stories. But for whatever reason, they naturally understand writing. Thus, it is absolutely possible for a person's first novel to be quite good. I remember on his blog John Crowley once said something like, "Writing is the only skill where you can do nothing--zero writing--for five years, and then come back and find you've gotten better at it." And I believe that. Our linguistic faculty--our use of words--is something that we practice every day of our lives. We even practice it by thinking (if you're a certain kind of thinker), and, for me, there's no reason to prejudge people and say, "Oh, you're gonna be bad at this and it's gonna be a huge struggle."
Secondly, lots of writers started later in life and still achieved tremendous success. And that is pretty amazing. Like, is there any other art for which that is true? I mean, if a thirty year old told me they wanted to be an opera singer or a ballet dancer or a concert violinist, I'd be like, "Hmm...I don't know about that." And even if they told me they wanted to be an actor or indie musician, I'd be pretty dubious. But with writing? Whatever, no problem. You can start at age 40 or 50 and still write excellent work. So go ahead, dream those crazy dreams! I won't stand in your way.