Why does someone steal? Because they believe that object they are taking will make them happy and so they want it around themselves. And so they just take it, even though it is not theirs. But, does the object make them happy for long? No. And so what? They have to keep stealing in the hopes that the next object will “do it,” i.e, give them that sense of lasting satisfaction that they so desperately seek.
Note that their desire for lasting satisfaction is legit and correct, but the way they are going about obtaining it is not. What the thief has yet to see is that what they really want, above all else, is themselves! The Self. What they ALREADY are and have always been. This will always be missed if we think what we truly are can be found inside any particular object, including our own body.