.. is noticing things others miss. The master chef notices the presence of an extra ingredient that makes the dish special, the master footballer understands the power of that extra touch, and the master presenter observes the little things that help make the presentation a hit.
I think the same applies to those who master living well. They notice the little things that make days great, they really appreciate people who make their lives better and, most importantly, they learn how to listen to themselves and interpret the signs their gut, heart and mind sends them.
Mastery begins with learning to observe deeply.