I have a couple of theories about jetlag. First, it seems to be worse if you're travelling against the sun (that is, from west to east). Secondly, it's made worse if you're tired. And in this respect, if you're tired when you board the plane, and are relying on being able to catch up on your sleep while travelling, it doesn't work. In my experience, if I'm tired when I get on the plane, my jetlag is worse when I arrive.
|Intercontinental travel without jetlag (Bosphorus Bridge, Istanbul)|
At present, we seem to be on track to recovery, on the rule of thumb that, when travelling west to east, it takes a day for every time zone that you pass through to adjust before you're completely normal.