Life is difficult. This is a fundamental truth, a great secret that nobody really tells you about. Life can be construed as a series of problems. You can avoid these problems, or you can face them. But the route that leads in the long-term to less pain and more joy is to aggressively seek out and solve them.
People avoid solving problems because they are painful.
Sometimes they cause physical pain, such as a medical procedure or a diet. Yet by wading into the pain and solving the problem, you grow. You excise the problem. And, if you continue to do this through life, you advance to a higher level. Learning to do this not only gives you your dissertation, but teaches you a wonderfully empowering approach to the rest of your life.