Dad was another WWII vet who did not especially care for the carbine. I regret having never prompted him to fully explain that stance. We shot one together on at least on occasion and he was a great deal less than enthusiastic about it, that I remember.
He loved his Garand and a guy from his company told stories of dad carrying a Thompson for some time at my dad's visitation.
A buddy of mine once brought his newly purchased Garand by dads house to show me. I thought he was going to panic when dad started stripping it down. Once he reassembled it the guy's question was simple - "how you do dat?".
