Those P38 can openers I grew up knowing as "John Wayne can openers". My Dad taught me to use one when I was very young, probably to keep me occupied. I'd "practice" on empty cans, because as some of you may remember, the tops and bottoms of cans were all the same then. Everyone in my first Scout Troop was taught to use them (Scoutmaster and both Asst.Scoutmasters were all Marine Colonels). When we went camping, if you didn't bring your "John Wayne" and knew how to use it, you didn't eat.
They bring back great memories for me and I grab them when I see them. Everyone in my family knows how to use them too. After all, gotta eat.