I did get a lot of sleep as a teenager, and I drank lots of milk so I'm tall thanks to it (5 years ago I'd voted 7-8 / 8+). But as an adult, I thought 6 hours were 'ok' but not good? I don't remember the last time I went to sleep before 12am, work up before 8am, naturally, and felt perfectly refreshed and not tired. I remember that feeling, I just don't remember how long ago it was, maybe 10-15 years ago even.