"The matter is a perfectly trivial one" -- he jerked his thumb in the direction of the old hat--"but there are points in connection with it which are not entirely devoid of interest and even of instruction."
-- Sherlock Holmes, "The Adventure of the Blue Carbuncle"
Immediately following this quote is a beautiful passage in which Holmes holds forth on little problems that may be "striking and bizarre without being criminal," citing three examples from the Canon.
Even when the adventures of Sherlock Holmes do involved crimes they usually aren't earth-shattering. In quite a few of his criminous cases, the crime falls far short of murder -- the theft of the blue carbuncle in this very story, for example. Holmes does at times tackle cases that affect the future of the empire, as in the matter of the Bruce-Partington Plans, but that is the exception rather than the rule.
Could it be -- just a thought here! -- that pastiche writers and movie producers overreach when they have Holmes foil conspiracies to take over the government or start a world war? Most of his cases, and the ones he seemed to like best, were trivial matters. Maybe this is one reason (in addition to the authentic writing style) that Vincent Starrett's "The Adventure of the Unique 'Hamlet'" remains my favorite pastiche.
As every Sherlockian knows, "The Adventure of the Blue Carbuncle" begins with the words, "I had called upon my friend Sherlock Holmes upon the second morning after Christmas . . . " Although this is one day early, I and my "Blue Carbuncle" Christmas ornament above wish you "compliments of the season!"