Why go to work??

We all know that there are many things that make the profession of nursing stressful, tiring, and downright exhausing. Despite all this, I am motivated to go to work everyday and do the very best I can because I enjoy the people I work with and I also know that the challenges I face (and the patients I care for) help me to become a better person. What about you? What drives you to remain a nurse? I mean aside from the financial and social responsibilities we all have.