You're doing what you love and, hey—you’re taking pictures, for goodness sakes. Most of the stress comes from having to pinch every penny. Although if you are that National Geographic guy, you might also have to watch out for Somali warlords.
Those weekly phone calls from your mother can also be stressful. "Are you still taking photographs?" "Have you gotten a real job yet?" "Your brother just got named Employee of the Month at his fast food restaurant—am I ever going to be able to be that proud of you?"