"Throw moderation to the winds, and the greatest pleasures bring the greatest pains." 

-Democritus

"One cannot find peace in work or in pleasure, in the world or in a convent, but only in one's soul." 
-William Somerset Maugham

"Appreciate again and again, freshly and naively, the basic goods of life, with awe, pleasure, wonder, and even ecstasy, however stale these experiences may have become to others." 
-Abraham Maslow

"We cannot be more sensitive to pleasure without being more sensitive to pain." 

-Alan Watts

"Except your awareness, all is accidental. Pain and pleasure, success and failure, fame and defamation — all is accidental. Only your witnessing consciousness is essential. Stick to it! Get more and more rooted in it. And don’t spread your attachment to worldly things."

-Osho