How is it possible to unlock one's front door with one's keys and then lose them inside one's own apartment?
I just spent the last hour searching for my keys / wallet. I used the same keys to unlock my front door maybe three hours ago, so I know they are in my house, unless something quite unlikely has happened such as someone climbing up to my 2nd story balcony and entering my apartment and taking my wallet without me noticing while I was playing guitar in the other room. (NOT likely)
You know you are in trouble when you are searching for something and get the sudden, excited thought: "Ah! There is one more place I haven't checked! Maybe they're in the freezer!" No luck. And then you find yourself looking through the washing machine multiple times just because you are so out of ideas.
This rather unfortunately means that I cannot legally leave my apartment (no foreigner registration card), have no money, cannot lock my front door if I chose to leave, and must figure out a way to make dinner out of what I have in my apartment. The latter being the most serious situation, naturally. ;-)