Of space and time
The journey to the airport until boarding the flight is much longer than the time it takes for a flight from Kuwait to Bahrain. Yet upon arrival no matter what the time spent your body still seems to sense a difference. Even road trips that stretches over miles would tire your body. There must be a scientific explanation but I always found it facinating.
Every cell in our body knows exactly where it is and would differentiate and take its role accordingly. Somehow our whole body also knows where we are on the map and tries to cope with our surroundings and adjust to them. It knows when a distance is crossed and when the time zone is leapt in a short time and so certain changes would takes place. That default homostasis works on many levels.
However, there is also the psychological factor with the changes of habits and surroundings observed be it in terms of a specific culture or a more universal trend. We all deal with this kind of information by comparing and contrasting, observing and describing inorder to understand and process this information. Perhaps only a few of our forfathers had the chance to travel yet today we might do it so often and are unaware of the constrain it might create if not dealt with properly.
I currently have to deal with travelling between London and Kuwait and have Bahrain added to the list as my husband is currently working there. The best way I can deal with these places is to know the difference in time and space. That my sleep would be different and so might my eating habit might be.
When it comes to my thinking hat 
I have to remember the environment that I am in and the purpose of my stay in each country so that I would have the right tools for each place and would not be carrying excess baggage. That means Kuwait is for family, work and research, London is purely for studies and Bahrain is my time with my Husband.
