I should have checked out http://www.craigkerstiens.com/2013/02/21/more-out-of-psql/ years ago. A challenge since it had not been written years ago, but there you are.
I resisted getting too familiar with SQL for a long time. This was arguably a mistake, although, in my defense, it the SQL model has a lot wrong with it. But I’m slowly coming around to appreciating postgres anyway.