If I can't die, I would not tell anyone I'm immortal, and eventually, someone would be pissing me off, and I would say: "You don't want to fuck with me, I'll show you what happens when you fuck with me." I then precede to blow my brains out in front of him and say "THIS IS WHY YOU DON'T FUCK WITH ME ************!" Of course, if I actually need my brain to function I would probably just appear dead for the week it takes to regenerate. But if I could function without my brain, I would probably end up doing it every time my brain regenerated.