IN JUNE, author Polly Dugan released So Much a Part of You, a confident, complex collection of linked short stories that capture how relationships—and people—change shape over time. In spring of 2015, she'll follow the collection with a novel, The Sweetheart Deal, about a drunken pact between two friends that's tested when one of them suddenly dies.

Dugan is experiencing a level of success most writers only dream of, but her path to publication wasn't a direct one: "I did a bunch of stuff in my 20s for like, 10 minutes," she says. When she turned 30, her mother encouraged her to pursue her interest in working with animals—"time's gonna pass no matter what you do," said her mom—a route that led her to Guide Dogs for the Blind, where she worked until the birth of her first son. (She wrote one of the stories in the book while on her lunch breaks.) In 2010—and 2011, 2012, and 2013—she attended Tin House's annual Summer Writer's Workshop, where she workshopped and polished the stories that would eventually secure her an agent and a two-book deal with Little, Brown.

AGENDA: When did you start writing fiction?

POLLY DUGAN: My first official attempt was my senior year at college. Bob Olmstead was the writer-in-residence at Dickinson, and two stories from the collection are significantly revamped versions of stories I wrote in Bob's class. I loved school but I wanted to get out in the world after graduation. Then I wrote on my own, but it was a lot of sentimental stuff about heartbreak, often very thinly cloaked and directed toward someone who had hurt me—the friend, the boyfriend, the parent. At some point I felt like I didn't have material that I could turn into anything that was even remotely interesting to me. The writing was pretty subpar and my subject matter was really limited. Writers, we do make things up, but you have to have some experience to draw from. I probably stopped chipping away at it when I was 25, then it was a long hiatus until 2006, when my kids were really small, but I no longer had a newborn or an infant, and so I had time during naps and when they went to bed.

You attended the Tin House Summer Writer's Workshop four times—why did you keep coming back?

Because I don't have an MFA, it's given me my education as a writer. That's where I got it. I was really, really nervous the first time that I went, and worried about holding my own, and it was amazing to have it validated by someone like Joy Williams that I wasn't wasting my time. At the same time, the lectures and panels give you such access to professional writers who are the first to share their stories about how it's an uphill battle. The other thing I can't say enough about without sounding like I'm gushing is that I made such great connections among my peer group.... Everyone who's interested should apply. It's so amazing.

Did you learn anything about yourself while writing these stories?

I'm kind of an alarmist and I have a lot of anxiety about losing things that are precious to me. Both of my parents are gone, and when that happens it kind of feels like loss impacts your DNA in a way that other life experiences can't. And then having kids, it's like, oh my gosh, if I had known I would be so worried all the time... if people could bottle that worry and make it birth control, it would solve overpopulation. One of the ways I exorcise all that is to put characters through incredible, extraordinary situations that ultimately they end up [surviving]. I don't know if there's anything I've learned about myself, but I've learned from my characters about continuing on. Which I know sounds sort of woo-woo and weird, since they're not real people... but I think if you're a creative person and you've got stuff going on, that stuff is going into your work. I don't think people approach creative work because they have a really happy story to tell. I think what compels you to creative outlets are things that, on some level, you're wrestling with.

One thing I really like about the collection is how complex all the stories are.

I'm not a writer or a reader who's necessarily inclined to enjoy things that get tied up. I want a sense of satisfaction when I'm finished, but it doesn't have to be tied up with a bow. I think it's most interesting if you're able to engage your reader in becoming part of the story. I don't appreciate being manipulated as a reader and I don't want to manipulate my readers, but if there's some ambiguity that sits with people that gives them something to think about and talk about after they're done reading... I guess being ambiguous is a way of saying, "Stay tuned, there's more." There's more to their lives, maybe in the book and maybe not.

Have you been surprised by any reactions to the story collection?

I guess [the interpretation that] the stories are dark, or that the stories have darkness. That's really interesting to me. I certainly have a dark side, and it's something that I kind of explore in the work, but I never sat down and thought, "Oh, these stories are really dark." I think they're just stories about life. My husband called them "unsweetened." I think a lot of really extraordinary things happen to these people that might be dark, but I think they end on a note of suggested perseverance.