10. In a former life, you slept with Henry VIII.
9. Finally! Somewhere to use that Medieval History degree!.
8. You have no aesthetic problems with putting 13th Century English coif on top of an 8th Century Spanish tunic.
7. You love paperwork, really, really love it.
6. The sound of an American accent does something to you ...
5. You could join one of those narrow-focus groups, but then you'd have to give away all your Norman gear, or the Nuremberg frocks, or the Viking ...
4. You already have a frequent buyer's card at your local fabric shop.
3. You can hit people in the head with sticks. Again and again. Legally.
2. When you get a leadership you didn't vote for, you wait six months and they go away.
1. If you want to get rid of all your spare time, income and shelf space in one hit; it's either join the SCA or have kids.
The above list was very slightly edited for content.