The biggest surprise to folks is usually the 24 hour layovers. Coming off domestic they look like no sweat. But look at some of those disputed pairings on the toolbox - we had one that went MEM - Osaka - Singapore - Osaka - MEM with nothing but 24 hour layovers. 40 hours of flying in less than five days, two 6-hour legs with no RFO, and every time you laid over you were going to work just about the time your body wanted to go to sleep. Trips like that take years off your life.....