Why it is hard to stay motivated in a PhD program

Completing a PhD can be one of the most difficult tasks in your life due to the fact in many cases it's simply impossible to keep yourself motivated to do the task. Here's why:

• Research is hard. It is hard to come up with something even marginally novel. It is very hard to adhere to the high standards for theoretical/logical strength of your arguments and empirical rigor of your field work. You have to work very hard, sometimes 7 days a week to adhere to those standards.
• Despite the fact that those standards are high, they are often ambiguous and subjective. It is not uncommon to receive completely orthogonal evaluations of your work. Some people will say that what your wrote doesn't offer any valuable contributions and lacks the rigor. Others will say it is great work and should be published immediately. I once wrote a paper that my adviser thought was worthless - it did not offer anything new. I sent the paper to a well-known journal and the senior editor told me it was very interesting and she will publish it immediately. The bottom line is that no matter what you do, you will be criticized.
  
• Despite the high standards that most researchers try to adhere, deeply inside you understand that most of the research produced in your field is really worthless. Deeply inside you understand that much of research is highly regarded only because it is produced by people who have a lot of power in your field. Nobody really reads those papers outside of your field, so there's no market validation of their value. The only people who read those papers are the ones who have to read and cite those "ingenious" papers if they want to get their own stuff published. So you start to doubt yourself and the field as a whole. If the most respected people in your field produce worthless crap, how can you produce something valuable?
• Despite the fact that you have to work hard and deal with lack of any intrinsic motivation, you have to live with no extrinsic motivation as well. You are paid peanuts for what you do. You are worth as much as a minimum wage laborer. Even if you succeed in completing your PhD degree, you will not be paid millions for your work. Most likely, you will end up with an average paying job, just like millions of other people.
  

In the light of these issues, one cannot help but ask himself or herself: "Why am I doing this?". Sometimes I think that in order to be successful in academia, you have to be somewhat of an arrogant imbecile. A person with deep intellectual and emotional understanding of these factors will never complete his or her PhD. So if you wonder why so many professors are arrogant and self-centric, this can give you a possible explanation. People who are not like that do not survive.