@freemo @Hawk1291 That's odd about the 45LC. That was the first pistol caliber I shot and at 11 it wasn't uncomfortable. It was fired from a Single Action Army style revolver so all the mass was likely the reason.
Same day as I got introduced to the AR-15 in the form of a Bushmaster. I remember that both were oddly comfortable to shoot for an adolescent.
Oddly enough, I didn't like 9mm at first because of how quickly the barrel rises but it's just part of getting used to a new caliber.
Perhaps it is just based on my experience with long rifles. It's not love unless it leaves a bruise and a little tenderness the day after.