Oh exposition. (Nope, you don't get a “Dear.”) You’re the guaranteed blah of stories, but it’s not completely your fault. Sometimes we writers load up our first few drafts with you. This is fine, because this is how we get to know our stories and see where they're headed. Yes, we USE you. And then we must cut you; I’m sorry. Actually I’m not sorry. Whenever I read you my brain goes a little fuzzy. If you had a face, I'd punch it. Sincerely; etc.
Exposition – which is explained background information – is boring. See; I just explained what exposition was. Wasn't that boring? Readers want to be entertained, not bored, so treat explanations and background information like . . . salt. (Also, treat clichés – like this salt one that is happening right now – like salt.) Sprinkle them throughout the story, otherwise “info-dumps” can happen, and those are NEVER fun. Especially in the beginning, when readers should be pulled in. And a heap of blah doesn't make for a great hook.
If you still find yourself going super exposition-y in later drafts, have a character SAY what you’re trying to explain instead. Twist an explanation into something more entertaining. Cut the explanation in half and see if it still makes sense. Give it personality. Save half of it for a later point in the story; intrigue is good. Succinctness is good. Exposition is not so good.
*Tip: Don’t make anyone read your very first draft. Just don’t. I’m pretty sure I owe my sister a kidney for making her read the Monstrosity of Terrible Writing that was my first draft (and, okay, the second one too). DON’T OWE ANYONE A KIDNEY. Or just give your first draft readers drinks and chocolate truffles and Chipotle and apologies. Whatever.