I've been reading here a long time and finally had something to contribute.
When my DH and I got married years ago, we planned a very low-key, casual event. My husband is very shy and hates crowds. I wanted to make sure he had a wedding HE enjoyed, too. The ceremony was immediate family plus two friends only, and we had balloons instead of flowers (he hates flowers with a passion).
Our plan was for everyone at the wedding to gather to pick out their balloons, and then we were to all walk together as a group to the ceremony location.
One of our friends decided this wasn't an acceptable level of formality. He went to my (almost!) DH and told him I had changed my mind and we were now to walk in a processional to the wedding spot. Then he came to me and told me DH had changed HIS mind and told me the same thing. Mind, this was five minutes before the ceremony.
Luckily my sister figured out what had happened, and everything went just the way we planned.