[Neo Nazi Hitler]

the only nerves that can 'provide feeling' around your brain is your skin.

You could touch your own brain and not know it (if your skull is cut open).

All you would feel is a break in your skin, on your forehead, or whatever.

Practically painless.

Easiest way to die of course is though c02 poisoning. You pass out, and then die later..

(edit: and no, this isn't the same as getting a kife through the neck.. you would feel that, kind of. It isn't like 10 seconds, you're thinking of a chicken or something.. it's more like 2-3 seconds. And your head would have no clue wtf is going on.. so it's basically painless also. But it's totally different then being shot in the head.. yay for biology, haha)