Experienced largely during a person's mid-twenties, denoting a period of a person's professional life where they feel they are pointlessly clocking in and clocking out, endlessly over what is viewed as an infinite length of time.
"I'm stuck in professional purgatory, Sue - however many jobs I apply for, I still have the cold sweat of having to wakeup tomorrow to do the same job that I hate, day in, day out"
"I'm so glad to have escaped professional purgatory; I've finally got a job where people give me a real wage, real responsibility and a sense of worth!!"