It is so possible. Even with cell phones. What if you were driving across country to some convention or something, got in a car crash, broke your cellphone in it, didn't have id or family that could identify you, and got amnesia. Mantra and Jordan are right.
Your definition affirms my assertion.
A. You still posess it
B. It's right where it should be
In the example given along with that definition, along with the connotation of this question, I think it means mislay, although in this case you would just be unable to find it because you can't exactly mislay a house. So it depends on how you look at the question. I am thinking that "lost" means unable to find. You can own the house, yet not be able to find it.
Well WW, let's assume that the guy with Alzheimer's knows he has a house, he's just completely forgotten where it's at.
And you can lose something but still have it in your posession...for example, say NASA sends a probe to an asteroid to have it bring samples back to Earth. However, something goes wrong and the probe can't thrust itself out of the asteroid, so it's stuck there.
NASA still "owns" the probe, but it's now lost. Naaaaah mean?