People

The most important single ingredient in the formula of success is the knack of getting along with people.
Theodore Roosevelt

Adversity 

Going through difficult times augments our capacity for pleasure: it keeps us from taking pleasure for granted, reminds us to be grateful for all the large and small pleasures in our lives.
Tal Ben-Shahar, Happier

Life

Our life’s a stage, a comedy: either learn to play and take it lightly, or bear its troubles patiently.
Palladas

Success 

If you wish success in life, make perseverance your bosom friend, experience your wise counselor, caution your elder brother, and hope your guardian genius.
Jospeph Addison