I have gone out without water before now, also went to a job 40 miles away and when I got there realised my battery was still on the bench in the garage charging.
Neither of these are as bad as the time I left the house at 5-30am and drove to cadwell park to a track day, signed on at 7am, went back to my van to get ready for the day, put my leathers on, then went to take the bike for noise testing and realised it was still on the trailer on my drive 45 miles away!!