Because your very patient big sister will allow you to sit on her lap forever while she plays Noggin.com games. This nets you:
* great cuddle time.
* nice photo-op for Mommy and that busy camera of hers with no extra work or fake posing needed on your part.
* a comfy and entertaining place to sit while you stuff your chubby cheeks with Cheez-its.
* major advantage over the other poor two year-olds who haven’t even heard of Noggin.com let alone begun to learn the finer points of winning at Diego’s Rainforest Adventure Game.