while I can't for certain state I know what death is, I can draw a conclusion based on observations. And at this point, until there is empirical evidence showing otherwise, it is where "I" cease to exist. We have no problems wrapping our heads around death when it comes to cows, chickens, road kill, but for some reason, when it gets to us, we invent spirits and souls and all kinds of crap to help us sleep at night. But find a dead cat near the dumpster... yeah, no problem with death then.