At the time of this writing, I'm going on four hours of sleep. I've gotten used to it, I think. I may get an additional hour now and then, but rarely more than that. As sick as it sounds, sleep deprivation seems the sacrifice for the blessing of two beautiful kids in diapers and a promising start-up business. But that sacrifice is not good, because I'm feeling it. I especially feel it when I do get an occasional eight hours of sleep. I wake up groggy and feel my routine's been messed with. I'm longing to feel rested and in …