Almost all behaviour is learned

I've just started reading Drawing on the Right Side of the Brain by Betty Edwards. She writes...

It's sometimes necessary to remind ourselves that Shakespeare at some point learned to write a line of prose, Beethoven learned the musical scales, and as you see in the margin quotation, Vincent Van Gogh learned how to draw.

And the margin quote is from a letter written by Vincent Van Gogh to his brother...

...at the time when you spoke of my becoming a painter, I thought it very impractical and would not hear of it. What made me stop doubting was reading a clear book on perspective, Cassange's Guide to the ABC of Drawing: and a week later I drew the interior of a kitchen with stove, chair, table and window - in their places and on their legs - whereas before it had seemed to me that getting depth and the right perspective into a drawing was witchcraft or pure chance.