I have two, which makes me DHP PhD, PhD. I never planned it this way, but no regrets! My first was in cognitive psychology. I studied human vision and visual neuroscience for years, and some of my research had value in the prevention of blindness and diseases of the eye and brain. I was doing ok, but I wanted to expand into things that had even more applied value for people. Also, academic jobs were quite scarce and I had emerging clinical interests in psychology, so I earned a second doctorate 10 years later as I re-specialized in clinical psychology. I was funded pretty well the first time, but the second time around was MUCH less stressful than the first. I think the two doctorates go well together as I study things that integrate both fields, and as I work as a cognitive scientist in a clinical psychology program. In the end, it isn't about the degrees, but about what one can do with the accumulated and combined knowledge and skills. Sure, I was in school for quite a few years (working, I might add). So far so good. My life in THE REAL WORLD is pretty good. I get to work on interesting things in a variety of areas that have value to the world, I get to learn and discover amazing things, I get to teach and train countless amazing students who will themselves make a dent, I get to have all sorts of amazing and intelligent friends and colleagues all over the world, I get to know that I can find good work anywhere in the world, and I get to never be bored. Not bad, and better than if I had stopped at just one mere PhD.... ;-)