There was a period in my life (almost a decade ago) when I was sleeping poorly due to unhealthy work habits and excess caffeine. I was in my 20s and early 30s during this time and felt invincible, but the effects on my body were profound. The damage became so tangible I had no choice but to make a change, and have for the last 5+ years been sleeping normally. I miss those days of nonstop work, I was more productive then, but it would have killed me if I had continued.