How do I know it had been reset?
Put something in the setup() to flash an LED. Then you will see it flash every time it resets.
However note that the reset function is only activated when this pin is low, to improve noise immunity on this simply change the value of the pull up resistor to say 1K.
ESD protection will not stop the processor pin from resetting it will only prevent damage in the case of a large voltage being present on the pin.