first one could be because in the situation your body would produce a lot of adrenaline into your body reducing the pain, and second one I'd guess it's because you got a surprise cut from the box cutter so your body is too late to give you adrenaline maybe.
Oh and by the way I hope you never have to get stitches on your calf muscle because the pain shots hurt so horribly bad… I nearly passed out and I am someone who can run 5 miles with 2 sprained ankles on my tippy toes-nya.
I'll keep that in mind never to mess around with my calf, although I've never broken a bone nor needed stitches for anything before which is surprising on my end.
I’ve had to get stitches 7 times In my life… the first time was my forehead when I slammed my head into a rusty chunk of metal on an old jungle gym… that was also the first time I got a concussion-nya.
Nonetheless I filled to bath towels with blood and I was 5 years old at the time… I surprisingly didn’t cry… in fact I remember asking if I had to go to the hospital… and when said yes I don’t think I have ever experienced disappointment more than at the time in my life… I’ve broken bones twice that being my nose and relatively recently my big toe-nya.