Não, não estou com a telha, estou com a pôrra do jetlag!

«Jetlag is actually caused by disruption of your "body clock" - a small cluster of brain cells that controls the timing of biological functions (circadian rhythms), including when you eat and sleep. The body clock is designed for a regular rhythm of daylight and darkness, so that it is thrown out of "sync" when it experiences daylight and darkness at the "wrong" times in a new time zone. The symptoms of Jetlag often persist for days while the internal body clock slowly adjusts to the new time zone.»

(in The JetLag Calculator)