The only interesting thing nearby was the bonfire in our garden, which is why "fire" ended up being our first contest theme. That's the banal, boring explanation. The more interesting one is that I chose fire because what's forged in fire is made to last (everybody knows that). Or because of this song that's played in a scene from Hot Fuzz that we often quote. Or because I wanted my friends to "burn with me", as The Doctor did. In any case: fire is a good way to start.