When you had a whole session planned, but your players just keep RPing
(comicpress.socksandpuppets.com)
Ice-cream is not anachronistic in your DnD games, it was invented over 2000 years ago in Rome.
My last session the party spent 3 out of 4 hours of the session sitting down to discuss their various issues that accumullated over the course of the campaign. It was nice, I had very little to do and enjoyed their roleplay.