JET-LAG BLUES EXPLAINED?

I have been uniformly told by many people that they feel much more jet-lag when they go to India, than when they come back here. I too experienced this when I went to India this time. There, I was begging for sleep for almost 4-5 days, whereas here, I was on my feet and back to work almost immediately. I was thinking about this phenomenon for a long time. At first, I thought it had something to do with 'travelling against the sun as opposed to travelling towards the sun' but it does not makes sense. Now I have come up with two possible explanations, quite simple ones, which I think may play a role:

1. Usually, flights from India to the US start at about 2.00 in the morning (plus or minus 2-3 hours). Since that is our normal sleeping time, we usually get at least 5-6 hours of sleep right after the flight starts. Then, when we reach our transit spot in Europe (Frankfurt, Paris, etc.), we are reasonably refreshed. After waiting for 2-3 hours, we board the connecting plane for the US, and again have a fitful sleep of a couple of hours. So we arrive in the US smiling and happy.
Now consider the converse. Flights from the US to India usually start sometime around 5.00 in the evening (plus or minus 2-3 hours). We are in no mood to sleep during that time. Now, we ARE in a mood to sleep about 5-6 hours later, when it would usually be 10-11 in the night and our normal sleep time. So we do fall asleep, but then we are rudely awakened in about 3-4 hours because we have reached our transit spot in Europe. There, we cannot fall asleep because we have to catch the connecting flight to India after 2-3 hours. We then board the flight and, irrespective of how much sleep we get now, our normal sleep schedule has already been disturbed, and we arrive in India much more groggy eyed. So I think the bottom line is that, in general, when we travel from India to the US, we somewhat maintain our normal sleep schedule and are more or less well-rested by the time we arrive. That does not happen the other way round. Since my assumption rests on the constancy of the time of departure, a way to test this hypothesis would be to take a survey and ask passengers who have departed from India and the US at times radically different from the usual times how they feel.

2. For many of us, I think that the other reason may be psychological. When we come to India, we are on a vacation. So we can afford to be much more relaxed and indulge in jet-lag. We don't care when and for how long we fall asleep because we are in the warm confines of home. That makes us 'take undue advantage of jet-lag'! On the other hand, when we come to the US, we have to be on our toes. There's backlog work to do, deadlines to meet, and appointments to keep. We cannot, at least mentally, be too much relaxed, and let jet-lag take undue advantage of us. We force our body to adapt to this comparatively draconian change, and resist complacence as much as we can. So we quickly adjust to our routine. Since my assumption rests on the existence of a sense of responsibility in people, a way to test this hypothesis would be to take a survey and ask people who don't give a damn about their schedule, irrespective of where they are, how they feel!

Q.E.D.??!