Defining Oneself

I am sure I've written of this some time back, but the question of how one defines oneself has been nagging at me ever since. How does one define oneself in a vacuum? While the more socially oriented or "realistic" folk would say that one cannot be defined in isolation, I would think that it's both sad and lazy to think of it that way. When one strips away one's career, friends, deeds and such, does one truly cease to exist? In my opinion, that is impossible. True, one may cease to exist in all the contexts mentioned, but one does still have a core of one's being that is independent of all the above. What's important is to constantly be aware of this core, and to constantly improve upon it. I know of people who commit suicide once they are stripped of their career and such, saying that everything that's ever meant anything to them has been taken away and that they have no further reason to live. For these people at least, they have no core to their being and are thus shattered by the move. They find themselves unable to pick themselves up. I define myself by my interests and my beliefs. Strip away the usual, and I have that core at the very least. Everything else about me is largely mutable. Should I be taken down to basics, I would find a new me to build at some point. Perhaps that simply means that I am not anchored at any single point, but it also means that I am slightly better at rolling with the punches.