Of course mate,some people really need that little sleep. I know few people like that,you are lucky. But not everybody can do that shit. I have tried it for years and all I got was dizzy feeling and fucked up headache with little to no energy. Every person has different tolerance and needs. I use no caffeine and alcohol, I have no apnea, I do intermittent fasting every day and sleep with no light in a room. I usually sleep 7-10 hours (depending on day,sometimes my heavy workout schedules give me overtraining so I sleep like a person in coma lol). It depends on my day usually.