Well yeah. But I don't live in a post-civilizational world of scarcity and starvation so I can pay a vet to fix my dog. If I was in Mad Max world I'd probably opt to eat non-allied humans since they're competing apex predators and the biggest security threat and I could take all their shit.
Your grandfather kinda sounds like a dick. Its not like you didn't shoot the best you could so I don't see the value in his lesson. You did your best to kill it with one shot and it didn't work out. The guy never hit anything but a bullseye? If anything it would just give you target panic. If it was about "put the boy face to face with yada yada" then why give you a rifle instead of a bow or a spear? Did he ever explain why, once you failed to give it an optimally humane death, the second most humane option of another shot isn't the way to go and it's best to do something slow and painful?
I'm sure it was memorable but I doubt it improved your marksmanship which it was his job as an adult to assess before taking you out.
He taught me a lesson to not make mistakes.
And to be fair i saw him shoot deer that were at half stride with a 243 at 100+ yards.
While inhumane it did teach me to respect the animal, by watching it suffer.
Where i grew up wasn't too far off from mad max to be fair.
Also, spending time in a slaughterhouse ruined me for a while.
It's more humane to just shoot a
wild animal in the heart.
Just cook your food medium and no parasites.
That's why everyone (except Rogan) tells you to cook wild game appropriately.
I can tell you this, if/when the apocalypse comes, i'll be one of the .00001% that will make it without suffering, just based on my childhood.
That's what my grandpa taught me, to be 100% self-sufficient.