This phenomenon is part of life for most, if not all, "country people" especially farm folk. Town clothes are like the modern equivalent of your Sunday best. I mean maybe not Sunday Sunday best, but certainly market day best.
Being a fairly new member of the country/farm folk demographic it's a newer, and therefore, more easily reflected upon part of my life.
So first I am going to talk home clothes or the non-town clothes. Untown clothes as it were. These can range depending upon the time of year and activity, but you can bet these clothes need to be functional and durable. Some aspect of home life, especially on a farm involves getting a little bit grubby whether from mud and dirt in the summer or wet from snow in winter or covered in wood chips, fire ash - whatever! They might be something like your camping/cottage clothes. The clothes for Rural grub. This means durable fabrics and sensible designs. Shit that can take abuse.
Home clothes are pretty self-explanatory because they are like city home clothes except no one can see you - so it doesn't matter if there are weird combos of colors/fabrics/ style. Its kind of like being a kid again, picking out your own outfits that your mum would likely be embarrassed of - It's all about what works in the end though. This makes me think of the external response to our fashion choices yet again. The public perception "what do my clothes say about me to others?" piece is pretty much non existent when it comes to country home clothes.
So now - town clothes. These are the things that you either can't, don't or shouldn't do any of the following in : fry bacon, wash dishes, bring in wood, cut wood, weed, plant, harvest, water or really go anywhere near the barn or garden in, feed animals (chickens etc), hunt, butcher after said hunt, operate tractor, have anything to do with poo in. I mean, we all try to avoid pooing ourselves wherever we are, but you don't want to pick up dog poo, shovel manure or touch anything to do with chickens in them. I think you're getting my point here.
These are the lightly colored, delicate fabrics, with more interesting design involving superfluous pieces that do not serve a functional purpose. Mmmm...superfluous. Adornment folks, adornment for it's own sake. Something we humans have always done. We like to look nice and whatever nice is, it's typically decided by the collective. Unless you're 6 and have a multicolored skirt that you live in because it looks like super kid ice cream!!! (my mum claims she burned it)
So your clothes communicate something about you to others. We all participate in this, knowing our clothing isn't the be all and end all of our "self" and yet we are so easily duped.
I can bet that if you were in a room of farmers (particularly) they would not be the carhart adorned, grubby faced folk you might expect if you went to their farm. This is because town, for farmers, is not the place to show your hardcore farmerness off by wearing your work clothes like some 2nd year university student. It's a place to socialize, go to market, it's an event. And events are things we dress up for!
Here's a story to try and illustrate my point:
Last year at market a friend from town was lamenting to myself and another farmer how it would be great if the market were on grass or in dirt (as opposed to the parking lot where it resides) because it would be way more fun to touch the earth with ones bare feet. I admit, as an avid barefoot-in-summer person, this notion had its appeal, but I felt something else. The other farmer articulated her response quickly.
"are you kidding?! I spend everyday dirty, in mud, dirt, water, shit- you name it! This is my one day to wear nice clean clothes, to see people and to get off the farm!!! look (gesturing) I'm even wearing earrings!!!!"
Where the pastoral becomes romanticized is an entirely impractical space and this farm life has little room for the impractical. I looked down at my town jeans that day and realized I had worn them into the field (bonehead) sloshed into a mud hole dirtying the cuff. As they were my clean town pair, I rolled up the pant leg and they were clean capris. I knew exactly what my farmer friend meant.
Sometimes we want clothing to communicate part of our identity and sometimes we want it to communicate or experience something for ourselves that we don't normally get to - for those of us who spend a lot of time in clothing that can take abuse - a pair of earrings and a nice outfit does the trick.