what number did john smith think he was first

John Smith always knew he was number four. Henry is his Cepan, and he would have known from the start, and have told John. Since they knew about Lorien, there would have been no secrets, especially not life threatening ones. He would need to know in order to protect John. In the movie, after three died, John saw him as his scar started burning, which was also not like the other two. If he really did not know, he would at least have known something was wrong then.