Books that have become classics - books that have had their day and now get more praise than perusal - always remind me of retired colonels and majors and captains who, having reached the age limit, find themselves retired on half pay.
One's age should be tranquil, as childhood should be playful. Hard work at either extremity of life seems out of place. At midday the sun may burn, and men labor under it; but the morning and evening should be alike calm and cheerful.
I think that the most important thing to teach children in an environmentally conscious age is alternative views of nature. They must be shown how our interpretation of natural systems is often completely dependent not on what is there but on what kind of box we draw around the data. And if they are going to be smarter than their parents, then schoolchildren must think subversively about accepted wisdoms concerning natural systems.