I was told this story:

A random variable can be compared with the holy roman empire: The Holy Roman Empire was not holy, it was not roman, and it was not an empire.

In the same way, a Random Variable is neither random, nor a variable. It is just a function. (the story was told here: https://www.amazon.com/Estimation-Control-Discrete-Mathematical-Sciences/dp/038796777X/ref=sr_1_15?s=books&ie=UTF8&qid=1488104698&sr=1-15&keywords=kalman+filter+springer)

This is at least a quippy way to explain, which might help people remember!

I was told this story:

A random variable can be compared with the holy roman empire: The Holy Roman Empire was not holy, it was not roman, and it was not an empire.

In the same way, a Random Variable is neither random, nor a variable. It is just a function. (the story was told here: source).

This is at least a quippy way to explain, which might help people remember!