Sleep need is variable, work is variable, motivation is variable. It's more likely that sleep is a spectrum, hence the 8.34% variance in required minimum sleep for adults, or how general quality of health affects ability to maintain sleep. It's even possible that sleep has nothing to do with our health and productivity other than being an indicator of it, and not necessarily a cause for it. Thanks, pseudo-scientific studies.
This is all true, but I think it's worthwhile to be very skeptical about your assumption of how much sleep is healthy for you. Everyone in these threads assumes that they are one of the special few who does perfectly fine on 5 hours of sleep.
