"How Watson Learned the Trick" is a Sherlock Holmes parody written by Arthur Conan Doyle in 1924.
Conan Doyle was one of several authors commissioned to provide books for the library of Queen Mary's Dolls' House;[1][2][3] others included J. M. Barrie, Thomas Hardy, Rudyard Kipling and W. Somerset Maugham.
A new version, a replica based on the miniature book created for Queen Mary's Doll's House by Conan Doyle, was published in October 2014 by Walker Books in collaboration with Royal Collections Trust (ISBN 978-1-4063-4597-1).
A scene very much in the manner of "How Watson Learned the Trick" is featured in the 1985 television adaptation of "The Adventure of the Resident Patient" in the Sherlock Holmes television series starring Jeremy Brett, with Watson attempting to apply Holmes's methods to uncover his friend's current state but largely failing, although Holmes does admit that "there is an element of truth in what you say".
The story was incorporated into an episode of the Imagination Theatre radio series The Further Adventures of Sherlock Holmes.