In presenting a story it is essential that the reader shall have some idea as to what it is about. To start by keeping the reader roaming along for a page or two among unintelligible remarks, and references to unknown or unexplained events, is to give him strong encouragement to shut up the book without troubling to go any further.
There is something very exasperating about a writer who gives no clue as to who anybody is or what anything is; he is every bit as irritating as the one who goes to the other extreme, and drags the reader through the babyhood and school days of the hero's parents.
These are the opening paragraphs of a MS. offered to me. It is quite a short story, hence there was every reason why space should not have been wasted on unintelligible preamble.
"It happened in this way: through the lions. No, that isn't exactly right though; the lions didn't really do it, would never have thought of doing such a thing; but if I had not gone to see them, it would never have happened. So, you see, they were to some extent responsible.
"I expect you are saying to yourself, 'What was it that happened?' Well that is what I'm going to write about. But first I must tell you that one of my failings from childhood upwards has been the habit of starting to tell my story right in the very middle; and then I always feel so annoyed when, after I've been chattering away for I don't know how long, people look at me and say, 'Perhaps you will try and be lucid and explain what you are talking about!' It never seems to occur to them that it is they who are so stupid. But I will tell you at once about 'me' and then tell you about 'it.' I'll begin at the very beginning, and try to tell you everything in proper orthodox style."
After much more of this description, it turns out at last that the lions were celebrities at a dinner-party where the narrator met the man she ultimately married.
That was all!
It is foolish to keep the reader dangling in suspense, unless the subsequent revelations are to be sufficiently striking to warrant the suspense. A long explanatory deviation from the actual theme is seldom satisfactory or desirable, in a short story, even when the theme is a big one (unless it be absolutely necessary, in order to elucidate some important detail): but it is inexcusable when the subject is trivial and obvious.
The more "body" there is in your MS. the more it will stand digressive or dilutive passages; the lighter your main theme, the less can you afford to allow the reader's interest to be dissipated over extraneous matter before you reach the main theme.