“Not everything that counts can be counted, and not everything that can be counted counts.”
Since my then girlfriend cut this out of a magazine and gave it to me it in an envelope to open when I awoke from having my left kidney removed at the age of 17, I thought this quote was from Einstein. It turns out it is not, but in fact from the sociologist William Bruce Cameron.
Anyway, I like it because I naturally tend towards leaning on science and data to explain things, and it reminds that that is not always best way forward. We can think beyond rationality without having to descend into irrationality.