Commentary on Meditations: B6:48

Whenever you want to cheer yourself, think of the qualities of your fellows - the energy of one, for example, the decency of another, the generosity of a third, some other merit in a fourth. There is nothing so cheering as the stamp of virtues manifest in the character of colleagues - and the greater the collective incidence, the better. So keep them ready to hand.

Before there was The Sound of Music and Julie Andrews signing "My Favorite Things" (when she doesn't want to feel so bad), there was Marcus Aurelius advising himself to think of his friends and their virtuous qualities whenever he wanted to cheer himself.  His entire first book in Meditations, is dedicated to reviewing all qualities and virtues of those he admires most.  I suspect he reviewed that section of his meditations often so he could "keep them ready to hand."