I am interested in one question.
How do we live a good life?
Good life in the philosophical sense means trying to find what we are most capable of doing, then developing that area, and attempting to use our skills and training to serve. By focussing on the question of how to live a good life, I began to be known as someone who could help people with their work. It started by solving problems, but grew into an emphasis on improved performance.
My PhD was a study of the ways meaning has changed over time. I looked at the transformation from manuscript to book culture, then compared it with the changes moving from book-based to digital information. The project required a lot of extra work, and a larger than normal doctoral committee, but it was a wonderful experience. For me, it was a study of how we know, and how we share knowledge.