Wisdom can only be obtained in measurable quantities from experience and the process of aging. I suppose it is because at some point in life man quits following and worrying about his little head and commences using his big head.

There is an old German saying "Too soon we get old - too late we get wise (smart)" - you get the idea.
The characters in this book are purely fictional but each was constructed from a collection of wise men I have known over many years.