I spend roughly half a week in the city and half outside (at my dad's farm), I also do as much outdoors activities as possible, luckily my family owns some land in the mountains which is a great starting point for hunting, fishing and long horse back trips (usually a week or so long, often longer).
When I'm at the farm, nobody gives my knife a second look. If they make a comment it's usually a question about the knife along the lines of "Where did you get it?" rather than "Why are you carrying it?". Even when I go to the nearby toewn for groceries I get no looks, hell when I'm carrying a traditional Argentine knife and riding my horse to the hardware store tourists usually snap pictures. The only knives that caused me some trouble were a Fallkniven F1 and a Frosts Laplander that had fully enclosed sheaths that an edgy policeman mistook for gun holsters, but I cleared the missunderstanding quickly and went on my merry way.
While hiking or hunting outdoors, I've had a few encounters with city folks who had some interesting comments about my knives, I just ignore them. Some people think that anything larger than a SAK is a fearsome weapon that has no use other than harming people. I worked as a hunting guide for a few seasons and I was appalled by the comments my own customers made. I had to put my fixed blade in my pack a few times, after all they were writting my paycheck.
I don't dress in military looking clothes, and I tend to carry 4" or 5" knives with nice shiny blades and natural handle materials. But that's just because I like it, if you like dressing up in camo BDUs and carrying a black bladed knife, that's your bussines and nobody else's. Sheeple can be educated, it takes time, but it is possible. I work with an American non profit organization and most of the volunteers and intern we get are college kids who want to live in South America for a while, usually left wing oriented and very anti-gun kind of people. Well, when they get here and meet me they are sometimes shocked by my knife habits, but after I've opened a gazillion boxes, fixed more things than they can remember with my multi-tool and nobody gets stabbed they usually relax and sometimes ask me for knife advice for their outdoors pursuits.