I’m not prefacing this because the title speaks for itself.
1) One person’s opinion is only one person’s opinion.
Most of the time, even if one reader hated it, others will still pick it up because opinions on fiction are subjective, not fact.
2) Even if a lot of people hated it, people will still buy it.
See E.L. James.
3) It got published.
Which means an agent, editor, book blogger, or reader loved it at some point. I realize this doesn’t safeguard against some self pubbed titles, but for the most part, someone read the book before the author put it on the shelf, and that person thought it was great. (But it doesn’t count if that person was your mom.)
4) People remember what’s wrong with something more than what’s right.
I speak from experience on this one, after years of running events with my husband, it doesn’t really matter what went well, people will still tell us all the little things that didn’t go well. Nobody will ever say something is 100% perfect.
5) You liked it, otherwise you wouldn’t have wrote it.
You’re the one that spent months, years, and countless hours slaving over your manuscript. At the end of the day the only person you need to please is yourself.
“It is better to write for the self and have no public than to write for the public and have no self.” – Cyril Connolly