Observing.

Don’t let athletics run away with you as you may see in nine cases out of ten.  It doesn’t amount to a row of pins.  What you want to do is slowly but steadily get ahold of the simple facts of nature by reading and observing and also get all you can from Grandpapa, who can probably give you more practical knowledge than lots of professors, and then when you come to the science part it will come easy.  This is also true in art.  I’ve lived in the country, closer to nature, among animals, etc., and have learned and observed lots of little, seemingly little, things that have helped me in my final scientific study.  Write compositions and stories of your wanderings in the woods and when you can, send one to me.  Do as John Burroughs does.  If you can get some of his books and read them they are wonderful.

You've got a most interesting future before you if you wish to make it so and I wish you all possible success.

N.C. Wyeth, from a letter to his brother Edwin, May 25, 1903