In my rush though, I over-simplified things! Silly me, this is about the Finnish language after all!
In fact, the Finns don't just use the adessive to create the concept of having (“I have a car” becoming “on me there is a car”). This actually only works where living things (humans, animals) are owners.
For inanimate objects, another case is used: the inessive. So when an object has something, Finns say “in that object there is something”, even if the something is not actually inside the object. Logical, huh?
So for example:
Talossa on ikkunat – The house has windows
(literally: in the house is [sic] windows)
BUT (because there always seems to be a “but” in Finnish)...
When an object has a given name, the Finns usually use the same construction as for living beings, e.g.
Laivalla on nimi – The boat has a name (literally: on the boat is a name)
So there you have it. The oddity has become even odder. And my headache has just got worse.