Sleep: we all do it, and yet somehow it's hard (as most of us can attest every morning). It's also really relevant: as thinkers, creators, and problem solvers, anything that makes our brains less effective matters. Missed sleep makes a difference -- even two fewer hours a night quickly produce measurable cognitive impairment. Things get more interesting when we look at why it's so hard: our sleep cycles are determined by our internal clocks, which often put us in conflict with society's timetables, leaving many of us in a state of "social jet lag", as if we'd been traveling a timezone or more every day. That's not how any of us want to code (or live), I think, and by understanding how and why so many of us are constantly tired, we can start to make things better.