LOL, it is a wonderful idea, but I have to admit, I stopped writing down when DS did most of this because it frankly scared me:). My husband actually took all the What to Expect books away from me before DS was a year old because I couldn't figure out why they didn't work for our child. I figured that I was misinterpreting what the book meant by saying 1 or 2 words by X months. Nothing made sense as I started to read too much into them and got stressed out trying to make them work for our child.
I do remember at his first B'day, one of his aunts said we needed to write a list of all of his "words" so we'd remember. DH and I started it and stopped after we filled up several pages and still hadn't run out of his words and phrases. That same morning, I remember DS sorting his Cheerios into piles of equal numbers and eating the ones that didn't fit into a pile evenly. I think he did it by 2,3,4 and 5 asking for more cheerios when he needed them. My sister brought it to our attention. DH and I were so used to it we didn't think anything about it since he had always done that with goldfish and Cheerios. Was he really doing math before he was 1? I'll stick my head in the sand and say no but the interest was there.
I don't think DH and I realized how proficient a reader DS was until we took him to the Smithsonian around 4 years. He was fascinated with reading all the displays especially in the early Life and Early Sea life rooms. Hearing him sound out and understand and discuss those displays sort of opened our eyes. Somehow the fact that he was reading Magic Treehouse books at 3 didn't have the same impact since everyone on both sides of family had been early readers:)