When you're about ten years old and shy, and your seventeen-months-younger sister is exactly your height, has exactly your hair and eye colour, and even looks a lot like you, and you've been bullied for months at school about how you MUST be lying that you're not twins, the absolute last thing you want to open on Christmas morning?
MATCHING. CLOTHES.
I adore my father's parents, but that was possibly the worst thing they could have given us for Christmas. Fortunately, someone must have had a quiet word with them, and the next year, we got books. Different books. (Actually, I think that year I was given Harry Potter and the Goblet of Fire, my introduction to that series.)