I love hot lime pickle, and eat it by the tablespoonful, but I will never forget offering some to a Vietnamese friend in the Mandeer restaurant in London; his faced screwed up so much that I thought it might actually turn inside-out ! I suspect that our individual reaction to the putative sourness of lime pickle is genetically conditioned, probably modified by subsequent exposure in those individuals for whom the genetic element does not rule out a repeat experience.
** Phil.