I felt nervous (and that everyone MUST know) at first, but not anymore. I have been careful to gauge the reactions of any/all people I run across in stores, etc. - as part and parcel of keeping aware of my surroundings - to try to get a feel for whether anyone notices. So far, I am pretty certain that NO one has noticed - most people seem oblivious and not very observant. The ONE exception was a lady clerk in a home improvement store, after I foolishly reached up to get something with my right hand (and probably exposed the muzzle of my pistol). Her look at my waist area betrayed that she probably noticed, but she did not treat me any differently. I was courteous and kind, as is my policy.....and I think that she was not put off by it (she did not seem to be).
I should add that, as others have said already, I have begun to be even more courteous, patient and polite than before, too. Somehow, carrying a weapon has, I think, actually made me calmer and more confident in my dealings with the world. I certainly want to avoid any confrontations, as before, but CC has made me more mindful of the possibilities - and more careful.