bloomsbury-international.com

JYMdj TIL that knowing something "By Heart" actually means to have a complete understanding of something before you commit it to memory, not that you have something completely memorized.
n07Y TIL the phrase “don’t spill the beans” comes from the ancient Greek practice of placing beans in a jar to cast a vote. If someone spilled the jar, the election results would be known prematurely.
7JKP TIL that the idiom “the cat’s out of the bag” is derived from a practice by some merchants who sold piglets in bags. If the buyer was distracted, the merchant would quickly switch the piglet w/ a cat. The buyer wouldn’t realize until they got home and let the cat, and not a piglet, out of the bag.