I’m asking because it’s a very normal thing to do here.
When you enter a room, but also things like a hairdresser or say a small cafe, you say hello to the people there and say goodbye when leaving. Or when taking a bus, you say hello to the driver and goodbye or thank him when getting off.
I was only recently told by some online friends of mine that this is pretty weird in other places. So I’m wondering if I’m (or my country) is the weird one or them
You don’t have to say that.
In the context of random people who don’t know each other, it basically just means “I acknowledge your existence”. Acknowledge their existence and you’re good.