I think you just get used to shopping dirty and tired after a while, and hope you don't offend anyone too badly.

I remember on one particularly long bike touring trip I was on, my friends and I struck up a conversation with someone, talking about where we were going, where we had come from, etc. After about 5-10 minutes, the person said "You guys are really cute, but you also really stink. I'm going to move over there."

If you are making your own dehydrated meals it seems you would be able to plan for more variety of foods. That way you wouldn't get tired of your options on a longer 30 day trip. I would also say though that you should expect to eat 3 times as much as you do on a normal day by the end of the trip. Something about doing something like hiking or bicycling for a month straight changes how your body treats food. I never calculated it, but I ate 5000+ calories a day while bike touring.