The act of working on, or relating to, one's Ph.D.

Primarily used by postgraduate students in an attempt to refer to the overwhelming amount of work they have to do in a lighthearted, and positive manner -- despite the realistic stress, pressure, and guilt that are ever-present during doctoral study.

Briefly, "the realization that each random passerby is living a life as vivid and complex as your own." Originally from the Dictionary of Obscure Sorrows, which has a lot more beautiful neologism definitions like this you might enjoy.