4. They will have strange friends.
5. They will go on dates and you will have to sit there awkwardly and talk to them while they get ready to go out.
7. Showing off your muscles is always fun.
8. When they sign up to do something it means you will have to get them there most likely. Even if it's at the butt crack of dawn and freezing cold outside.
9. When they do amazing things like run in the Seattle 5K it makes you very proud.