@starshaped yeah, and it can be kinda hard to find studs through plaster. In our house we've got original plaster walls with drywall over top of them. So that adds a bit more fun to it!
If it helps, if you get a stud finder, it's usually possible to find studs! Between that and checking for studs anywhere between 16-20 inches away between other ones, you can usually find them.