This is a question that I have been answering with the brush lately.
If a scene, or a tree, a face or whatever draws my attention, why don't I always try and paint it? or at the very least, draw a sketch of it. The answer has been laziness and hesitation for the most part. It's easy to make excuses like, "I don't want to have to set up my paint, or clean it all up at the end." The truth is that's loser talk. None of the painters I admire would fool themselves into thinking that it's too much effort to get to work on a painting. But these days, my love of painting and creating always wins over any annoyance of setting up my paints.
And all these studies and sketches that I produce are all for the greater good of understanding nature. It also trains my brain into realizing that I won't be dissuaded by some nonsense like "It's too hot outside to paint." So nice try, brain, but I'm too damn stubborn to be put off.