Assuming, as you grow older, that you're the guardian of the world's wisdom, even if you haven't necessarily lived enough to know what's right and wrong.
Thirty spokes meet in the hub. Where a wheel isn't is where it's useful. Hollowed out, clay makes a pot. Where the pots not is where it's useful. Cut doors and windows to make a room. Where the room isn't, there's room for you. So the profit in what is, is in the use of what isn't.
There is a saying in Tibetan, 'Tragedy should be utilized as a source of strength.' No matter what sort of difficulties, how painful experience is, if we lose our hope, that's our real disaster.
Alas! it is not till time, with reckless hand, has torn out half the leaves from the Book of Human Life to light the fires of passion with from day to day, that man begins to see that the leaves which remain are few in number.