A PhD is required if you have any hopes of teaching at the college level or academia in general. Lots of people sacrifice money for fame and their contribution to society. The lucky few who become Harvard professors or such do become wealthy by most people's standards; or at least they live very comfortably. Believe it or not, but no, it's not that rare a thing to want to get a PhD because you love teaching. From all of my experiences with various graduate programs in various schools, many people do start their PhDs because they want to share what they've learned with other interested students. For the longest time, I was the same way too. And teaching the few undergrad courses that I did only made me want to teach more, as there is just something genuinely.. good..for lack of a better descriptive term, about being able to impart what you've spent so much time and energy on to others, and to see in their eyes a similar passion or interest as your own. The problem that I've found from spending so much time at major research universities with this, is that many of these same people, once they actually do become professors, discover just how much of their job is teaching-oriented and how much is ´scholarship-oriented. At the larger institutions where research is emphasized, chances are the faculty there will likewise be more concerned with their own research then they will with teaching their daily courses. The reason for this is, I think in part, at least, that old-school "publish or perish" mentality, whereby you are measured not by your teaching prowess, but by your scholarship. Plus, scholarship is still the primary criteria by which faculty are evaluated for possible promotion to tenured positions. And....No, a PhD is no guarantee of anything other than that the person was able to survive the PhD program. My advice? Run. Run while you still can. Run as fast and as far away as your legs will take you. Having a PhD doesn't mean they are automatically geniuses. However, it probably means they have quite a bit of knowledge in THEIR field. You all disparge these people because they don't know EVERYTHING in EVERY field. :)