Then, of course, if we will insist on long-haul there's the 3-4 days (if you're lucky) of body-clock mayhem when we return. I managed a day at work then had to call in sick with the almighty mother of a migraine. We still can't sleep and we've been back a week! (Maybe that's just depression at the thought of real life catching up with us again).
Note for self improvement: dump the negativity!