Numbers of cities visited on my most recent trip: 4, not counting Copenhagen where I was only at the airport.
Number of nights where I got less than 4 hours of sleep: 4.
All the days where I traveled from one city to the next. Edinburgh-Paris, Paris-Marseille, Marseille-Istanbul, Istanbul-Copenhagen-Århus.
My most relaxing times in the last few months were the times I spent in Århus. I was, for the first time in years, not sleep-deprived. But when I traveled, not just this trip but previous trips, my sleep schedule was disrupted.
This is a one consequence of flying Ryanair and other discount airlines: their flights are always scheduled for very late at night or very early in the morning. I'm sure it's because airport space is cheaper during this time. Of course we all complain ... and still take Ryanair flights anyway.