It always amazes me how crew can still look so smart at the end of a flight. My office is close to the hotel crew nightstop at in Berlin and it amazes me how they can have done 3 or 4 sectors and look like they're ready to start again!

I also don't know how they manage with all the time zone changes plus working through the night. Particularly Mixed Fleet who can have a TATL night flight a day or two off followed by a couple of European trips then be off eastbound!