We renewed our son's US passport for the first time today. This is the one where you need to bring progressive photos.
So when it was our turn at the window, the vice-consul asked us a few questions and then wanted to speak to our son. Then he started going through the progressive photos asking him questions like 'Who's that?' 'Do you remember this?' and so on. And our son was answering 'I don't know'. 'I never saw them before' and stuff like that.
Our son thought it was a joke, and that's because he thinks *EVERYTHING* is a joke. So he was buggering about with the answers, and possibly nearly blew it for us.
When he got to the photo of him and the cat, the vice-consul asked him the cat's name and he answered it correctly and then launched into a story about the cat. So finally the vice-consul was satisfied.
So my advice is that you should tell your 5 or 6 year old when you take them for a new passport, that when the man asks questions, it's not a joke.