It’s a good thing I’m a fast reader because lately I’ve been reading way too many bad books.

Smart people, people who make a living by reading books, tell me I should stop doing this, but I can’t: I finish every book I start. I see the wisdom in advice that there are too many good books to waste time on bad ones, but I do it anyway.

The problem may be that I tend to be a completist: Watching TV series to the end of their seasons. Faithfully completing book club books I didn’t vote for and suspect I’ll hate. Always cleaning my plate. Rereading every one of Agatha Christie’s mysteries in order and writing about that. And, to the best of my recollection, never bailing on a play (I have walked out of precisely one movie in my life, and that was because I was with my dad, who insisted “Tango and Cash” was never going to get better).

My only semi-rational explanation is that once I’ve invested enough in a book to tackle it — meaning it’s been recommended to me, it’s by an author I like, or I read an intriguing review — I want to know how it turns out, and I’m always hoping that even bad ones will improve.

In truth, this rarely happens, although I was gratified a couple of months ago when it did with Ben MacIntyre’s “The Spy and the Traitor.” MacIntyre repeats himself and much of the setup of his nonfiction story — about a KGB double agent whose intel helped end the Cold War — previously appeared in John Le Carré’s lightly disguised fiction. The good news? The book’s second half was as riveting as the best of Le Carré, even if I’d argue for a sterner red pencil on the first half.

Most, however, do not get better. In fact, I have no statistics to back this up, but I’d argue that books — like movies and plays — are more apt to start out well and then get bad than the other way around.

The worst-case scenario for my book-finishing mania is what’s been happening lately. I’m in the midst of a terrible streak in which nine of my past 10 books were OK or worse, interrupted only by “White Houses,” Amy Bloom’s splendid fictional take on the relationship between Eleanor Roosevelt and Lorena Hickok.

Only one of the 10 was a complete dog but, looking at my recent Goodreads history, it’s hard not to ponder which of the books in my enticing stack at home I could have been tackling instead of, say, André Aciman’s lackluster “Enigma Variations.”

In my defense, I will say that there is satisfaction in finishing every book, even if the best part is sliding it into a Little Free Library and hoping that whoever grabs it next will like it more than I did. If there’s an implied contract between writer and reader, I know I held up my end of the bargain and if there was something to be learned from the book’s mediocreness, I learned it.

But it would be perverse of me to urge my bibliocompletism on anyone else. In fact, I like the policy of friends of mine who have a “10-minute rule” for TV shows: If they’re not into it by then, they stop, never to return again. I’m not sure what the book equivalent is — 50 pages? Whatever the bar is, I’m living, reading proof of the old proverb that says, “There is no friend so faithful as a good book. There is no worse robber than a bad book.”

What about you? Do you finish books no matter what? Or do you have a certain number of pages you commit to before packing it in? Write us at books@startribune.com and include your name and city. We’ll use your comments in a future column.