The baby book!

I feel so bad. Most of my daughter's baby book and journal is completely filled out. With unbelievable detail. Like the exact date she did things for the first time. My son's books not so detailed and not so filled out. I want to do it. And it drives me nuts that I haven't. I'm at the point now that I can't for the life of me think of what to put where though. What he did when is all a blurr! I feel horrible about it. And what's worse is I probably won't be able to figure it out.