You don't love yourself enough. Or you'd love your nature too, and what it demands of you. People who love what they do wear themselves down doing it, they even forget to wash or eat. Do you have less respect for your own nature than the engraver does for engraving, the dancer for the dance, the miser for money or the social climber for status? When they're really possessed by what they do, they'd rather stop eating and sleeping than give up practicing their arts. Is helping others less valuable to you? Not worth your effort?
V, 1 - Meditations (c. 161–180 CE) - Book V (Hays translation)