By no means do I mean to suggest that I've mastered or perfectly adhere to either of these principles - far from it. But I find these to be underdiscussed principles of living richly.

Cultivate "intellectual vitality."
I recall, while working as a tour guide while an undergrad a Stanford, the admissions department discussing that the single thing they most looked for in candidates was not ability but "intellectual vitality." The desire to learn about things and participate in things in an active, constructive way. While getting my haircut the other day I overheard an exchange between two people discussing baseball, and the conversation was so bereft of any curiosity -- it was a social script followed blindly. Which is not to decry sports generally, those of my friends who are intellectually "vital" and enjoy sports can talk about them with a perspective and a rigor that excites someone like me who never watches a game. Exploration is a key trait to nurture in a child -- it's the key to their living a life that is self-enriching and boundless.

Practice mindfulness.
David Foster Wallace's commencement address at Kenyon University in 2005 is a brilliant summary of the challenges and choices we face as an adult. It is imperative not only to give a child choice but to help them to realize the significance of those choices and their ubiquity.

No excerpt does the speech justice, and I think it should be required reading for any college grad, but I'll include his opening remarks, which give a flavor of the whole:

"There are these two young fish swimming along and they happen to meet an older fish swimming the other way, who nods at them and says 'Morning, boys. How's the water?' And the two young fish swim on for a bit, and then eventually one of them looks over at the other and goes 'What the hell is water?'

"This is a standard requirement of US commencement speeches, the deployment of didactic little parable-ish stories. The story turns out to be one of the better, less bullshitty conventions of the genre, but if you're worried that I plan to present myself here as the wise, older fish explaining what water is to you younger fish, please don't be. I am not the wise old fish. The point of the fish story is merely that the most obvious, important realities are often the ones that are hardest to see and talk about. Stated as an English sentence, of course, this is just a banal platitude, but the fact is that in the day to day trenches of adult existence, banal platitudes can have a life or death importance, or so I wish to suggest to you on this dry and lovely morning..."

from Wallace's This Is Water