Always wash fruit/produce before you eat it?

I was just told by the produce guy at Whole Foods that it is unnecessary to wash my berries before I eat them because they are organic. This seems suspect to me. Then he went on to say that if I wash my berries and do not eat them all in one sitting that they will go bad faster since I washed them. Is this true? Also, my organic berries may not have pesticides on them, but they could have pee or god knows what else on them. I was always taught to wash my fruit before consuming it. Whaddya you think?