This "fear" is not so much the feeling of being afraid of someone as it is a quality of reverence, respect and high regard and an implication of social boundaries. When you gkrehng-jai, you have consideration for someone, and this is shown in considerate behavior toward that person. You may, for instance, be reluctant to impose on someone by asking for a favor, or you may refrain from doing something that you feel may overextend your boundary or cause someone embarrassment or to "lose face." This person for whom you have high regard may in turn reciprocate with considerate behavior toward you. Gkrehng-jai is a very important value in maintaining harmonious social relationships and one that has a protective quality among the people involved. It accounts for the high degree of politeness and civility you see in exchanges among Thai people everywhere.