Thousands of years ago, when we were smashing rocks to make knives, probably.
We’ve never been an intelligent species as much as a dumb branch of apes that happen to give birth to some glitched individuals with a form of intelligence every now and then. But jesus fuck, the last years, with the unversal internet access that we achieved, we became dumber than ever.
Most modern AAA games with some degree of exploration tend to use yellow (or any bright colour, but usually yellow) paint to tell a player where to go.