For readers, the misplaced modifier is the best grammar error of all. No author, however, wants to become the butt of an unintended joke by making mistakes like these:
Walking up the stairs, the clock struck twelve.
Standing next to the window, the lake was stunningly beautiful.
One morning I shot an elephant in my pajamas.
Obviously, clocks can't climb stairs and lakes can't stand next to windows. And unless you're Groucho Marx, elephants can't get into your pajamas.
Readers, however, tend to connect and associate words near each other. For a subtle example, compare the following sentences:
Daniel almost ate a box of donuts.
Daniel ate almost a box of donuts.
In the first sentence, "almost" modifies the verb "ate." In the second sentence, "almost" modifies the phrase "a box of donuts." By rearranging just two words, the author forces Daniel to eat several thousand extra calories.
Always double check your syntax and word order--and never give your readers any inadvertent reasons to laugh.