Backpacking provides many uplifting sights, sounds, and experiences. However it also brings its share of irritations and adversity which can detract from the experience if we let them. So it's important, especially on a long-distance hike, to provide enough comfort for yourself to keep your spirits high.
We don't use the term "comfort food" for nothing. Eating, and the satisfaction you get from eating, is one of the most important things one can do to maintain a happy feeling on the trail.
Sometimes hikers get obsessed with things like calorie density and getting the thousands of calories you would need to replace the calories you are burning. I, at least, can't eat that much. Thru-hikers apparently get a big appetite after a few weeks on the trail but for most people, even on a hike lasting up to a week, that's not going to happen (see a related post by SectionHiker here). I find that I eat about as much on the trail as I eat at home, perhaps just a touch more.
I think we need to worry more about WHAT we eat. Basically you are happiest if you eat very similar things to what you eat at home. On my West Rim Trail hike I brought pop-tarts for breakfast. Many hikers favor them because they pack a lot of calories. After the second day I could hardly face them. My hiking buddy Chris was eating cold cereal for breakfast with powdered milk that he mixed-up. That was really what I wanted because cereal is what I normally eat. So on my Susquehannock trail system hike I brought powdered milk and cereal and was much happier. I took some Archer Farms granola single servings like Brian recommends on his blog (tastes great and provides lots of calories) but also some stuff I just had around the house.
I also think the evening meal should be a warm meal. Won't energy bars provide as many calories without the fuss of a stove? Perhaps, but there is something nice about eating a warm meal before bed, even in the warmer seasons of the year. It's what we do at home so we should do it on the trail to keep our minds and stomachs happy.
Perhaps our ancestors, who went months without bathing, would not be distracted by dirt and sweat. But for us modern folks it's pretty distressing to be really dirty. Now we have to be practical here. We can't bath every day on the trail or pack clean clothes for every day. But we can do a few things to help us feel human.
Chris and I had wonderful weather on our hike. But even at 69 degrees F you are going to work up a sweat on a steep climb. It's not so much the sweat that is the problem, it's the layer of salt that builds up on your skin. That tacky feeling is unpleasant and can cause chaffing. So one thing Chris and I did frequently was to stop at a water source and take an upper-body sponge bath when we felt dirty. I used soap on my face but just plain water on the rest of my body. It's amazing what clean skin can do for your outlook on life.
I also brought along two pair of quick-drying nylon mesh underwear. So after a particularly sweaty day I could wash the one I was wearing and change into the other, letting the first pair dry. Not a big weight penalty but a big difference in happiness and comfort.
If most of us are honest we would have to admit that it's harder to sleep in the woods than in bed. Perhaps this wasn't true when I was a kid but a good night's sleep is harder to come by as an adult. Lack of sleep makes even the nicest day in the woods a burden so we have to learn to sleep.
For one thing the woods are noisy and that can be quite a distraction when trying to sleep. I've found that a pair of foam earplugs work wonders. They don't block all sounds but they are very good at the high pitched sounds made by many insects and critters scurrying about in the leaves.
If you worry because you don't sleep well on overnight hikes then take hope. Chris taught me, and I found that it is true, that your body adapts fairly quickly. The first night won't be great but the second is better and by the third night you will find that you sleep amazingly soundly. I had brought along a book to read during sleepless hours but by that third night I was asleep within seconds of lying in the hammock.