I'm not entirely sure what point you're making. That's not physical law in the same sense – nothing compels you to take something from me (or prevents you from taking something from me if you're sneaky or strong enough, as you said).
On the other hand, you and I can't both have the same object even if we wanted; it has nothing to do with ability or circumstance.
edit: I should clarify that you and I can share something in the sense that we can freely give it back and forth, but if we have one shovel, we can't both be shovelling at the same time (and can't share it at all if we live far apart). And if we're talking about food, well, we can't both take the same bite of bread.
On the other hand, you and I can't both have the same object even if we wanted; it has nothing to do with ability or circumstance.
edit: I should clarify that you and I can share something in the sense that we can freely give it back and forth, but if we have one shovel, we can't both be shovelling at the same time (and can't share it at all if we live far apart). And if we're talking about food, well, we can't both take the same bite of bread.