[aruanan]

Lots of amps in a car battery, but only painful if the voltage is jacked up.

Think of the sparks made by connecting battery cables when jump-starting a car and then imagine one battery cable attached to one's toe and the other one approaching one's penis and tell me what's not going to be painful.

[Old Professer]

Wipe two fingers of each hand with a slight smear of Vaseline and then grab both terminals of a 12 volt car battery; you will feel nothing. Press yur fingers as tight as you can and you may get a tingle.

Now, clean your hands with a degreaser, sand your fingertips until the skin is fully abraded and try this again.

Voltage is force, resistance is the key to effect; very high voltages seem to travel over the surface without trying to burst through - see Tesla's high voltage experiments for some graphic examples.