[ylow]

A PhD is one of the hardest, yet most rewarding time of my life. Its perhaps the only period where I have the opportunity to do nothing else, but "think"; where I can spend many months just reading papers, learning and attacking what seems like one little problem. It is very hard work, no doubt. Going back in time, I would still do it again. And in fact, I have seriously considered doing another PhD in an entirely different field.

But still I generally do not recommend people do it. You have to be in it, because you are very interested in the field. You have to feel rewarded by learning, and by solving problems. And also there is a lot a lot of luck involved: advisor, topic, ideas etc.