I think teenagers and pre-teens. Those years were really hard on me. You want to be accepted by your friends at school and you want to be cool but thats hard to do when they see you going door to door and you know you cannot celebrate holidays.
My son is 13 and when he is with me he is a normal kid. He has friends, he is allowed to talk on the phone to kids at school. He can celebrate his birthday and have Christmas with me. I wish I had a choice when I was his age.