When we have chosen the vocation in which we can contribute most to humanity, burdens cannot bend us because they are only sacrifices for all. Then we experience no meager, limited, egotistic joy, but our happiness belongs to millions, our deeds live on quietly but eternally effective, and glowing tears of noble men will fall on our ashes.

Writings of the Young Marx on Philosophy and Society, L. Easton, trans. (1967), p. 39 - Reflections of a Youth on Choosing an Occupation (1835)