grammar-monster.com

Oodv6 TIL, the phrase "balls to the wall" originated from early aircraft pilots and their ball-ended throttle levers and actually has nothing to do with testicles.
9YEnM TIL the phrase "Until the bitter end" doesn't refer to feelings of bitterness, but instead is a Nautical term referring to the end of an Anchor, known as "The Bitter".
XE4bP TIL: In 1696, William III introduced a tax which required those living in houses with more than 6 windows to pay a levy.To avoid this, house owners would brick up all windows except 6. As the bricked-up windows prevented rooms from receiving any sunlight, the tax was known as daylight robbery.