Yêu is chasing after the moon. Thương is running as hard as you can because you promised to catch it. Tình is feeling for a moment that you just might. Nghĩa is knowing that reaching the moon is a feat of engineering; by all accounts it is mostly craters and dust; the best thing about it is on the way back seeing how fragile earth is.
Nghĩa is, wax or wane, drinking up the moon from a shared cup.