One of the memory tools is called mnemonics, which is a Greek word for “of
memory”. Mnemonics works by attaching the words or ideas to something familiar,
like a song or a picture or the rooms of a house. Here’s a picture that visually
separates the months of the year into those with 31 days, on the knuckles, and those
with less than 31 days, in the indentations between the knuckles.