I was looking at some older pictures the other day with one of my daughters (Lauren) when we ran across a picture of her with her sister.
Now, Lauren and Jessica have always given us a hard time when we make a mistake as to which is which. Initially they just ignored us -- so if Jessica was 3 feet away and you were saying "hey, Lauren", she would just ignore it, even when you repeated it several times, getting louder each time (and Lauren was nowhere to be found so she had to know you were talking to her. Later, they look at you with this disappointed look like "how could you?" and say "I'm NOT Lauren."
So, I thought turn-about was fair play and asked her "hey, which one of them is you?"
Lauren stared and stared as I said "You mean you can't tell which one is you?" and "Are you really Lauren or are you Jessica?" and on and on (I was having a good time with this, if you can't tell).
Eventually she guessed (with a 50/50 chance) the right one (and was quite proud of herself when I told her it was right). But I think the lesson was learned. Perhaps the next time I will tell her she was wrong, even if she was right (just to see how she takes it :-) ).