I guess that would make me a P,B & J...
Interesting, though. When I had my 10mm CCO built, I had every intention of ONLY carrying it, focusing on the 1 system to the exclusion of all others so I could presumably, become exceptionally proficient with it. I did this for several years.
Prior to the CCO, I carried whatever struck my fancy that morning, and I have all types of handguns: revolvers, DA autos, DAO autos, striker fired autos, SA autos, etc.
Now, however, I find myself carrying more of a hi-cap, DAO semi-auto, usually a 3rd-generation S&W 6946, or the marginally smaller 3953.
All that being said, I understand the desire/urge to focus on one & only one system, but at the same time, I like the fact that I can pick up any of my handguns, or anyone else's for that matter, and I remain more than reasonably proficient with any of them.
As I explained to one of my kids while teaching them to drive (we had 4 completely different vehicles at the time and she ONLY wanted to drive in one of them, because that's what she felt most comfortable in), one needs to be able to get in to any vehicle and be able to adapt & drive it because you don't always get to be in the same car all the time. I think the same holds true for guns.
Sam