灌水灌烦了，看看这篇文章吧： http://www.cs.indiana.edu/mit.research.how.to/section3.13.html
Research is hard. It is easy to burn out on it. An embarrassingly small
fraction of students who start PhD programs in AI finish. AT MIT, almost all
those who do not finish drop out voluntarily. Some leave because they can make
more money in industry, or for personal reasons; the majority leave out of
frustration with their theses. This section tries to explain how that can
happen and to give some heuristics that may h
