Studies about sleep are often just crazy. When did people stop using their common sense? Just have as much sleep as you think works for you.
My Grandma walked to the supermarket the morning of the night she passed and was totally lucid for the entirety of her years.
That's assuming you do become senile and unable to do anything useful. Doesn't necessarily have to happen, and that doesn't mean you shouldn't live a good life.
> Studies about sleep are often just crazy. When did people stop using their common sense? Just have as much sleep as you think works for you.
What's considered "common sense" can vary greatly from person to person, and people aren't always aware of how their habits can have long-term negative consequences on them.