Before saying we understand all the fundamental physical forces in our universe

People in the Middle Ages thought the Earth was flat,
that bees were little birds and that
evil spirits lived inside Brussel sprouts.

Until the 1920s, the universe was believed
to consist only of our galaxy.

When I was in elementary school,
I thought camels stored water in their humps,
that carrots would improve my eyesight and that
an earthworm cut in a half would grow into two new ones.

Before 1991 there were 9 planets in the solar system.

Before 2004 eight glasses of water a day would keep you hydrated,
before 2005 stress could give you an ulcera,
before 2006 you would experience taste in different parts of the tongue.

Last year scientists discovered the Great Barrier Reef has been bleaching
for the past 400 years.

What else may we have got wrong?

(NaPoWriMo day 2, for  the A to Z Challenge and napowrimo.net)