Light Switch Pairings

I spent a couple of weeks at my parents house near London over Christmas, and something I always remember about it from when I was little is that in the hallway and the landing there are two light switches - the one on the left of each is for the hallway and the one on the right is for the landing. Now, if you switch the left switch at the bottom it turns the hall light on. Then if you either flick that same switch again OR switch the left switch upstairs, it turns it back off again. It's just common sense; it's the way you expect it to be. My own house has a similar system for the corridor light, that there's one switch next to the front door and one next to the living room and switching either of them will reverse the current state of the light. I did go to a place once that had recently had the electrics renewed and they messed up somewhere, that if you switched the hall light switch downstairs and the lights come on, flicking the hall light switch upstairs does nothing. But then switching either switch again does not turn off the light. As such, both switches are positioned as absolutes, where both have to be up for the lights to be off, but if either or both are down the lights are on. It boggles the mind. That is what it has been like trying to use Windows this last couple of days just for something as simple as gamescreen capture, after using Macs exclusively for the past 6 years.