It comes from an old song I heard when I was way, way younger than I am now.. and it always made me think.. and I never forgot the sentiment. It's pretty deep really... the more we find out the less we know.. It also reminds me of the motto I used to have on my monitor, back when I had one, 'The true sign of intelligence is being aware of what you don't know.' That's very much something I have internalised... that I am always learning and the more intelligent you are the more you know that there's so much you really don't know and haven't even touched upon.
Not here to have a go at stupid people but you do find that stupid people are the opposite.. they think they know it all and tend to be absolutely convinced that what they know is completely right... this tends to be because they have oversimplified and are not aware of the surrounding factors and issues.
So, the song...
