Damager,
I think I can agree with that. But, body fat is natures way of storing up for the next backpacking trip.
But, this points out an alludued to, and stated by Ryan, degree of systemization with UL or XUL backpacking that has not been well explained. You wrote: "In summary I feel the SUL mindset is a combination of skill, fitness, and a well thought out gear list working in harmony to create an enjoyable, memorable trip."
To me, I see this as a statement that, like many here, all components of backpacking are important to the "having fun." Not only the gear, skills, and fitness of your body. But planning, completion and even storage of gear are important considerations.
Planning is when you decide you want to go packpacking somewhere. It involves logistics, material resouces available, what you need to purchase, plotting a route (tentative as it may be,) and other facets.
We talk a lot about gear, here. Soo, I'll skip an explanation other than to say the local, elevation, forest cover, etc will effect that.
Skill is about the same. We trade a lot of different techniques here. Knowing how to shit in the woods for example.
Fitness is another one. This comes up at different times.
Completion of a trip, knowing what worked well and what failed adds to experience and skills. Unpacking gear, cleaning gear(if needed,) and noting what needs to be refilled/resupplied.
Stowing gear can be important by the time we get to UL or SUL weights. We usually have enough gear to make selections. Putting it all in one box doesn't work. If you cannot find your wood stove when you leave, it doesn't make much sense to even *have* the stove.
These are systems that are not as interesting, not as vital, to a backpacking trip, but, without them, a trip can quickly loose the memorable quality.
For all these, a good system of making sure each thing gets done in it's correct sequence is used. Sure, we all forget stuff, like I forgot to get gas, or I forgot to get a new lighter. Systems make things easier to remember as well as more efficient to use. You are alluding to this quality about backpacking that is often ignored by simply listing things to take. Using a pad as a pack frame, is a classic example of where this breaks down. There is no clean way to join these two components together in a simple list. Secondary usage or dual usage should be considered, then the gear list will look like Ryans, 11 items plus personal preference. With these bloody computaters, it should be possible to do better by taking a lesson from database normalization.