Our modern fixation with getting eight solid hours’ sleep – you may be glad to hear – is nonsense. Healthy sleep can range from six-and-a-half to 10 hours a night. Teenagers need around nine, but as we age we sleep less.
Why? I suspect because memory consolidation, and the processing of new information, are two of the main purposes of sleep, and in our more mature years, we simply come across less that’s new to us.