Ethan's trying to read

We got a library book which was about trains. It has just a few words on each page like, yellow tanker car, blue boxcar, black steam locomotive. I read it to Ethan today and of course he loved it. After I read the book I told him I thought he could read it all by himself. He said "no I don't know how to read". I said "just look at the pictures and say the words mommy did". So he thought he would try it. He did really good, and "read" the whole book. I know this may not seem like a big deal, he is 4 years old, but it is for Ethan. He loves looking at books and loves to be read to, but has never sat and "read" a book by himself. He has always said "I don't know how to read". Hopefully he will try "reading" other books now.