How does electrocution (fatal) happen?
The amount of current needed to kill is not some exact number.  It is around 20mA.  One person will die at 20mA, another lives despite more current flowing through his body.

Body resistance is not fixed, either.  On a cool, dry day where you don't sweat your skin resistance will be higher than on a muggy day with the sweat pouring off your body.

220VAC can push enough current through your body and through the ground (the literal ground or floor under your feet) to kill you.

Never work on live 220V circuits.

Have all 220V circuits in a closed, insulated or grounded container when they are operating.

Have a ground fault interrupter installed in the house wiring or outlet you use when experimenting.

Your "theory" that people are only killed by touching live and neutral is wrong.  If you rely on live to ground being safe, then it will kill you one day - and before that, you will experience painful shocks from the current that isn't quite high enough to kill you.



The ground wire in your house is connected to the ground (literal ground made of dirt outside your house.)  

The ground wire is connected to the neutral wire in your house.

Your house and the floor are connected to the ground, and thus to the neutral.

Grabbing the live wire while standing in your house is therefore the same as touching live and neutral.