Entropy Explained, With Sheep by Aatish Bhatia.
Entropy is relevant to information theory, encryption, Shannon, but I mention it here because of the cleverness of the explanation.
Aatish sets a very high bar for taking a difficult concept and creating a compelling explanation that does not involve hand-waving and/or leaps of faith on the part of the reader.
Highly recommended as a model for explanation!
Enjoy!