From a religious standpoint, why are my feet so ticklish?

It is a sign that you do not have a vocation, or that you do, depending on which sort of monastery you wish to enter. Monasteries established under various sets of rules have had the habit of testing the novices' vocations by tickling their feet during prayer. Then some groups dismiss the novices who are too ticklish, while others keep the most ticklish ones and dismiss the others.