Just an interesting fact, I recently bought a few tons of grit.....now don't laugh, I'm not trying to take away from the post or the TED talk.
In fact the grit was bought for the reason of taking very soft sand, and making into a harder, more sure surface, on which cars can drive and not get bogged down in the soft beach sand.
I think this fits nicely into the idea that we need grit to succeed in this world....