At one of my military postings, captains shared a duplex with each other. The units were mirror images of each other. We actually had no real neighborly issues with the other family. I fixed all of their three children’s bikes, straightening out handlebars, putting oil on the chains, air in the tires, adjusting seat height and minor things like that. They were very grateful since their military father did not own any tools. I was doing standard maintenance on my kids’ bikes, so it was no big deal.
They were rather needy and borrowed our vacuum cleaner all the time. One of the boys would come and get it and drag it across the front yard from our front door to theirs. It was an upright vacuum, and the small wheels started getting caked with dirt from being rolled across the yard. It was rather annoying to have to clean the dirt from our vacuum before we could vacuum our own home.
The Army issues one traditional gasoline powered push lawn mower to each duplex. The mower had been stowed in my unit’s carport when my family moved in. Each family just took it whenever their side of the yard needs mowing.
While the Army provides the lawn mower, it’s up to the residents to buy the gas. I bought a small 1½ gallon gas can for $5 at the post exchange gas station and would fill up the can when I needed to mow.
The other family never bought gas for the mower. They would just take the mower and use it until they finished their lawn, or it ran out of gas. They would then leave it in the yard where it ran out of gas. It would stay there until I needed the mower and brought it back to my car port to fill it up.
On the backside of each carport, was a small storage shed for various yard tools like rakes, hoes, snow shovels and room to store kids' bikes. This is where I kept my gas can. Their kids had seen my gas can in there when I fixed their bikes.
They started to help themselves to my gas to mow their yard. Usually it was no big deal, but when I would go to mow my yard, both the mower and gas can would be empty. While the cost of the gas wasn’t a lot, it was just a pain to have to get gas every time I needed to mow.
I started filling my gas can with just enough gas to put in the mower to mow my yard. God, that was so petty to just put less than a dollar’s worth of gasoline in that can instead of filling it up, but I had just had enough of their mooching week after week for years.
Previously, when I needed to fill up my car, I’d fill up the can too. It wasn’t like I was spending less than a dollar for gas. I’m filling my car and putting maybe a half gallon or less into the can.
After I finished mowing, there might be enough gas left inside for them to start their lawn, but definitely not enough for them to mow their entire yard. Then when they would get my can, they’d see it was empty and then not finishing mowing their yard. I’d see the mower left in the middle of the yard and roll it back under the carport before nightfall since I was responsible for the mower.
One weekend after their yard was getting overgrown, the mother asked me about where I got gas for the mower. I told her I bought a can at the gas station and filled up the can when I filled up my car. Then it dawned on her that they had been using gas I bought all these years.
EDIT: This incident happened when I was in Alabama (1997–98). Today (August 23, 2024), I filled up that very same gas can at Walmart ($2.86/gal) and it reminded me of this answer.
When I fill up my car, I fill up this can first and put 1½ gallons into it. Then I fill up my car. That way, I don’t put too much gas into the can. I ended up putting 1.47 gallons in the can.