Sometimes I start to think of incoming calls as interruptions. Sometimes I don't FEEL like being helpful or solving problems (my own or someone else's). Sometimes I don't FEEL like taking the extra step.
I ask myself the question, "Do I want to do this for a living?". That question puts things in perspective. Maybe one day the answer will be "no" and I will have to plan an exit strategy. So far, the answer has always been "yes".