Too smart for his own good

Over the last week or so Gavin has taken a real interest in the human body and how it works. It has been a lot of fun for me because it was an interest we share and I felt like I finally knew more about something than he did. He has a couple of children's books about the human body, but after basically memorizing those, he decided to start reading my college Human Anatomy textbook. He has posters of the different body systems hanging up all over the house, so I figured it couldn't hurt to let him flip through the textbook. So, last night at dinner he suddenly says "Mom, what are sperm?". I just about choked on my chicken and said "Where did you hear that?" He said "I was reading about the reproductive system in your anatomy book and I saw that word and I don't know what it means." I said "Well, that book is for adults and sperm is something you will learn about when you get older, but you don't need to know about it now" He said: "Mom, if I'm smart enough to read an adult book, don't you think I should know about sperm." I said "No, I don't" and quietly hid the textbook in the top of my closet. Hopefully we can put off the "Birds and the Bees" speech until at least first grade.