Am I dreaming， or did it use to be stronger? Twenty years ago， it seemed like a good dose of jet lag could mess you up for a week. After six or seven hours in the air， zooming toward the sun or away from it in a pressurized cigar tube with carcinogenic upholstery， you were useless.Remember? Up was down， black was white: By night you rebelled against the clock， by day you floated like a ghost... It seemed to last forever. No question of getting any work done:Your body might have arrived at its destination， but your consciousness was apparently still up there somewhere， still in flight， with the thin air and the ice crystals.