Sleep: we all do it. It's easy, and yet - as most of us experience every morning - it's somehow really hard too. It's also very relevant: as thinkers, creators, and problem solvers - people whose fundamental job it is to use our heads - how our brains work is a subject of huge importance. This is a scientific tour through recent scientific research (with references, of course) on the effects and causes of sleep restriction. Sleeping even six hours a night produces measurable cognitive impairment in most people; it gets worse as you sleep less, to the point where some parts of your brain are constantly functioning like they hadn’t slept in days. Who'd want to code, let alone live, like that? Things get even more interesting when you examine why it's so hard to get a full night of sleep - how our internal clocks and their adjustment mechanisms often in conflict with society's timetables. So many of us end up in a state of "social jet lag": missing sleep every night as if we'd traveled a timezone or more by plane that day, constantly tired and never sure why. We spend countless hours optimizing our development environments to get maximum efficiency. Shouldn’t we treat our most important tool - our brains - the same way?