Everything fits perfectly. I always wonder if I'm employing my time properly in academia. But they keep me too busy to think about it deeper. Research also keeps anyone tired, too much time dealing with the same problem, lacking some fresh air once in a while to breathe. We are emotionally involved with the work, loyalty and devotion and so on. Intermittent rewards when some of your articles are accepted... And the real awards are distant, the Ph.D. itself.