If you fuel your Chrimbo shopping on a bag of Thornton's Butter Tablet, the following will happen:
1: You will get all your shopping done.
2: You will, surfing the sugar rush, barge into the wrong shops, look around in a startled manner, and bellow, "Sorry! Wrong shop!" in a slightly Tom Baker manner.
3: You will lapse into a diabetic coma mid afternoon.... goodnight...