The Circle of Fifths is an chart in music that rotates around the notes in fifths.
It is an important diagram that musicians can use, as it can help them know how notes relate to each other.
If I had infinite time I would learn and better understand the circle of fifths from the following tutorial:
Michael New concisely explains uses for the circle of fifths.
-Introduction to how it's made
-Mnemonics for memorising its order
-Finding the sharps and flats for each key
I'm pushing art, so unfortunately I cannot memorise it at this time.
But I think it's a great idea, and so I will post it to share the knowledge.
Maybe in future I can revisit this post for myself. Then I can learn it myself and become a better musician.