I'll never forget the first time I landed in Heathrow. I got, maybe, an hour's worth of sleep and then had to schlep our luggage from where we were dropped off in Covent Garden to our Airbnb and up flights of stairs. It was around noon I think when we finally were settled. I took about a two hour nap and then went exploring London on foot while my wife slept. I just could lay there and sleep when there was so much of the city to be explored. Yes! I simply can't function without at least six hours of sleep in my daily life.