Why ancient Egyptians slept on stone headrests

Nothing ensures a good night's sleep quite like resting your fragile skull on a literal boulder. Wealthy Egyptians used rigid headrests carved from stone or wood to elevate their heads while they slept, purely to avoid having scorpions and lice crawl into their elaborate hairdos. Chiropractic care didn't exist yet, but apparently chronic neck pain was infinitely better than a spider in your ear.