What’s something most people don’t understand?

If I had the answer to this I would almost certainly be far too busy to live a normal life. Explaining the ‘something’ to most people would take a lot of time and effort.

Better to concentrate on the things that I don’t understand and give myself a little mental upgrade. Most of my contemporary understanding arrives accidentally at my door. I often wish I had understood something better years ago.  But am always grateful that late enlightenment has arrived.  Pondering helps.