I already HAVE a Father...

This is going to be short... I know. You think I can't do short, but you will see that I can.
Anyway... I went to a convention, not very long ago. I won't say which convention and I won't say where.
But, while I was there, I wore a shirt which was emblazoned with a dragon, and the little witticism which warns us "It is never wise to meddle in the affairs of dragons, for thou art crunchy and taste of chicken."
I had a few people chuckle at the shirt, and say they liked it. I like it too. That's why I bought it.
One man, however, stopped me and enthused, "I love your shirt! I so love that saying! I live my LIFE by that rule!" Can anyone tell me, based on that statement, what type of convention I was attending?

More later.