My daughter recently turned 2. She has known all her letters, and colors since about 18mo. She has been saying the Pledge of Allegiance for a few months, knows most shapes, speaks in 3-8 word sentances, knows the difference between who is a boy and who is a girl, Counts to 20 (14-16 all sound alike though), regignizes some numbers 1-9, remembers EVERYTHING, knows 30ish childrens songs, understands concepts like on, off, under, next to, up, down, etc, draws straight lines and circles, loves to pretend, likes to play with other kids, pretty good at sharing, LOVES books, has been gentle with paper books since 12/18 mo, knows 20ish animals and their sounds, I can't even count how many words she knows. She probably had the vocabulary (at least number of words) of a 4 year old. etc. etc. etc. She is just too smart!
She goes to preschool 2 mornings a week for the social aspects. Her teacher seemed suprised the other day that she knows her colors.
I have taught preschool and recently worked at a daycare. She was smarter than all the 2yr olds and many of the 3 and 4 yr olds when it comes to actual "book knowledge".
It's kinda nice to see someone else with a child that is also advanced. She can't spell her name and just recently started pronouncing it somewhat clearly but, it's not an easy name. Her name is Elizabeth.