When we get cold or when we feel a little threatened, we get 'goose bumps'. Experts think they come from a time in our evolutionary history when the human race, as a whole, was significantly more hirsute. Those bumps would cause our hairs to stand on end, thus providing greater insulation and should we come across an enemy, we would look bigger and more impressive. These are about as useless to us now as the reactive mechanisms that cause us to worry and fret - i.e. not very! Don't indulge such feeling.