A second amen.
My pack yesterday...fleece jacket, vest, wool hat, first aid kit, cellphone (in airplane mode or off), GPS, camera, repair kit, toilet kit, compass, a couple of methods of fire starter extra food and maps of the general area...real 7.5' quads. This load is a few pounds heavier than Bob's...with the 3 L of liquids.
I go out with the knowledge of the overnight low temperature for the highest elevation I am going to and the forecast for the next few days. I also know where the water sources are and their current condition.
Last weekend, four groups totaling 14 people were lost in the Mt. Baldy area causing SAR call outs. All these folks were trailwalkers who lost the trail and continued deeper into the abyss, not recognizing they were no longer on the trail. Many were without the product clothing for night time temperatures. This is not unusual.