Actually it's down to a multitude of things FBF
and they don't tie the tubes the cut end of the vas deferens are either sewn, left open or cauterised, left open is thought to be "kinder" from a congestion and chronic long term pain pov.
DH had the number one consultant in Staffs do his, there was a fair bit of rummaging and the left tube is always more tricky than the right, even the doc doesn't know exactly why.
It also depends if you get an infection and if you are a fast healer/how good your circulation is.
My BIL was the same as you, no problems whatsoever, looking at the stats, you were the lucky ones. 
It still makes me chuckle that people are still told that it only takes 20 or so ejaculations to clear out any old sperm
. Again it depends on the man's physiology, the older the man, the less powerful the ejaculation and the longer it takes to clear.
OP, women don't have the monopoly on genital pain, I've seen DH on the floor with chronc orchitis and would take childbirth and a 3rd degree tear any time.