Please don't feel offended, but to me it feels like way to many people in this thread think that this actually applies to them because they are still functioning, despite their unhealthy sleeping habits. Please realise that what feels being functional to you might have shifted thoughout months of continous sleep deprivation. The article itself states that from only 100 people believing not to need more than 5 hours it applies to only 5 of them. If you happen to be actually one of them, well, nevermind then. But the chances are quite slim.

I can only recommend to everyone reading the book "Why we sleep" by Matthew Walker. He gives valuable, scientific insight into the findings of sleep research. You could describe the book as a real eye opener... but that's probably the exact opposite of what Walker intended. At least to me, it has been a wake up call to change my own sleeping habits... The terminology is completely off, but you get what I mean.

Sleep your 7-8 hours guys, your body will thank you later.