I loved drawing when I was young and still enjoy it. Those quotes hit home with me because drawing makes me see things beyond the shapes we have in our heads. Lollipop trees are irregular, with branches veering up, or sideways, or down, depending on the type. The sky has a thin lighter border next to the horizon. A person's eyes may be wide set or close together, tipped up or drooping down at the corners, and the almond shape is not such when drawing a profile or three quarter view.
Do these things matter? I guess they're a lesson to see things as they really are, not the way we have them in our heads.