"The best time to plant a tree was twenty years ago. The second best is now."
That proverb is ancient - it has been around for centuries (if not longer).
[1] Ancient Chinese proverb [2] Abraham Lincoln [3] Albert Einstein [4] 4Chat/Reddit/Twitter
4chan gets a lot of credit as the origin for various things which I don't think it deserves most of the time.
"The best time to plant a tree was twenty years ago. The second best is now."