Dreams are like puzzles and sometimes you can find any of the missing pieces for some reason.
I have silly nightmares all the time so I know how you feel. D: One was about my friend's and my fantroll and I woke up screaming "MAKE IT STOP!" However I will not mention what happened or I'll have more nightmares.
Whatever the dream was maybe it was because you where thinking about the guild and while sleeping your brain just sort of clicked. :T
I know this doesn't help but I hope it makes you feel better! Having bad dreams are the worse especially when your unsure why it happened. : (