Why are little sisters so annoying? SIGH…

I mean, I should know! I have two, and well, my older sis acts young enough to be smaller than me! But no, I, the older, more mature (sometimes) sister is left clueless about this vitally important piece of information.
If only I knew how they ticked, I could have some control over them. But I don't, so they continue to ruin my life - except, somehow, I always get blamed. I mean, they have their good points; though from my point of view I could count them on a finger on my right hand. Let me think...
1) they are related to me.
2) errr..... ummm.... seriously, I can't think of anything else!


Could some of you little sisters out there clue me in? I'd appreciate it, and I'm sure Orange would too.
Pink Jellybean xx