I have only ever really felt bad about wasting a salespersons time ONCE and it was just because they truly hit 'home' for me. I was in Forest City, Pennsylvania for regular work and there was a nice bonus on a Chevy shop. I picked up the shop and no one in this town could have known me from Jane Smith. It is a good 11-12 hours from my house by car.
The shop said to wrap up and not take up too much of the sales persons time -- 30 minutes was preferable. I tried to wrap up after a really good shop. The salesman I worked with appeared to be 65-70 years old and even mentioned retiring soon. He took his time, seemed to think I was genuine about the car, went through all the motions that I went through at another dealer when I really did buy my Equinox -- Just an overall fun guy to work with. We looked at cars, took a test drive on the automatic and on a standard that someone had ordered and returned, and he knew a ton about the vehicles and changes made in recent years. He also knew a ton about my particular car and sold me on the newest model of it by mentioning storage, new features, etc that he had picked up by glancing over my Equinox. Guy coulda sold me a new SUV and I would not have been mad.
Anyway, shop is wrapping up, he's giving me info, his business card, telling me when the sales are and when their best pricing is, telling me about bonuses off for being a student, extra off for owning a Chevy, yada yada and then suddenly says "can I ask you a somewhat personal question?" I started thinking what on earth he could be about to ask me. Then... guy says "your accent is kind of unique... you sound like you're from where I grew up at." I laughed. There's no way that is a possibility so I asked him, "well, where did you grow up at?"
He replies.. "______ County, WV in a place called **town**-- then we moved to a little house near X______." I am pretty sure by my expression he must have known the name was familiar to me. It isn't where I live now, I used a fake name for the shop, my plates are not attached to the area, literally no way to identify or connect me with this area since my license/car/learners/home etc are all in another state. I thought he had to be joking; **town** is the "city" (it has 1800 people) closest to my little farm town at about 25 miles distance and X______ is a tenth of a mile from my grandparents homestead. I seriously thought he was messing with me. I told him where I was from and he started naming off all sorts of businesses, people, and places in the area, and stood talking to me for another half hour. He really was from the area I grew up and was so excited to meet someone else from there. I left feeling excited there were people from my town up a little more north in the city, but also kinda sad that I wasted his time. He probably was hoping I'd come back and talk more.
ETA: I blocked out the town name 1) because I don't want y'all coming over to visit my grandparents even though they'd feed ya

and 2) because even though it is the name of the town, it's a somewhat derogatory name from when the area was coal camps and segregated. The city/state still haven't gotten around to giving the place a new name...