Also the less pain you feel the lower your blood pressure and heart beat can stay, that helps pumping less juice out of you.
When my finger was done I had to turn away to keep chilled, so it was bleeding a bit- but noticeably less.
One guy even gave me a magnifier and his needles for me to inspect, so I am worried about them less. Sounds weird, but it actually works when you (not) think about it.