Something I can relate to, all right...

I've only ever had one shot in my life, but I can still feel it in my arm.

I've only ever had one too. It was hugely anticlimactic, gotten in far more pain through clumsiness/stupidity...

I know how Cirno feels. I dislike needles to.

I used to be afraid of shots.
One time, like 12~13 years ago, I was in the doctors office kicking around like a little kid (I had a outright phobia, okay?) and then the doc simply states
"What are you fretting about? I gave you the shot 10 minutes ago."
...I had never felt it.
I've not been afraid of shots since.

I feel your pain, Cirno. Shots hurt.

Nostalgia pool?