There's nothing like graduate school to make you feel the blues.  Except a colicky baby, a hole in your lung, your dog dying, the wife leaving you, the bank repossessing the farm, losing your job and ending up in graduate school, or hipsters.   We are three physicists, one engineer (emeritus graduate student), and an information scientist.  Even when we thought we escaped the "real world" by going on to graduate school, we found we couldn't shake the blues.