Many years ago, when I was a small child, I heard this joke:

When is a door not a door?
When it’s ajar.

Unfortunately, at the time, I didn’t know the word ‘ajar’. So, through a combination of misremembering and simple ignorance, I would be found parroting the joke in the following fashion:

When is a door not a door?
When it’s a jam jar.

While I would like to think this was me displaying an early taste for surrealism, the truth of the matter is that I was just a simple mind poorly understanding the art of humour, and clumsily engaging in a cargo-cultish simulation of comedy.

Today, on April Fools’ Day, I am reminded of this story.