Have you come across any information that seems to challenge or overturn any widely held notions?

On your travels through life, or through the beautifully vast amounts of readily available information that we, now, have available to us, have you come across any (Out-of-the-way) information, alleged or otherwise, that you would like to share? Ideas that grip your interest and move you to think deeply about them.
Ideas that you feel would be of more general benefit or interest if more widly known.
By way of a ‘starter’, I would like to offer the notion of ‘The Aquatic Ape Hypothesis’ with regard to human origins.

p.s I tried to illustrate this with a link, but didn’t quite manage it
But please don’t let that put you off looking!.