The irony of the phrase "I'll sleep when I'm dead" is that if you deprive yourself of sleep, you'll be dead sooner. And when you're dead, you're not sleeping. And you're not writing either.
For whatever reason we have a tendency, creatives in particular, to default to sacrificing sleep at the altar of our work before anything else. God forbid we binge watch Netflix less or stop bringing our smartphones to bed.
The trouble is, we're doing more harm to our health and our creativity by burning the candle at both ends than we realize.