Interchangeability

One aspect of running the material side of life I've come to have more appreciation for is interchangability. The ability to use one part/piece/thing in many different other parts/pieces/things. Some examples are using Type AA batteries. At one point I bought a CR123 flashlight, thinking the batteries were superior and for some reason it was just cooler than a normal AA/AAA flashlight. I used it until it went dead, then somewhat questioned "why did I buy this? It runs on somewhat obscure batteries that are more expensive than others?".  At that point I decided to get rid of it. in favor of AA and AAA flashlights. That was the only CR123 powered thing I had, so by getting rid of it, I could get rid of the need to keep a cache of CR123 batteries on hand, reducing complexity of my battery storage regimen. This is maybe one example of increasing interchangeabilty in my life. Maybe another example is shotguns. I dont really know why a person would prefer to have a 10, 16, or 20 guage shotgun aside from having the 10 for bigger water foul or such. Why would a person not just buy all 12 gauge shotguns. I think they are arguably the gauge of shotgun that's had the highest production, their ammo is everywhere. Lets say you have a 12, 16, 20,  gauge shotguns and you want to have a few different types of ammo on hand for each one. Maybe a lighter bb count ammo on hand for birds, a slug on hand, and some 00 buckshot on hand, that's three types of ammo per gauge. That's 9 types of ammo for the guns, where if you instead chose to have three 12 gauges on hand, you'd only need the 3 different types as they can be used in any of the three guns. One more example might be electronics chargers. I can see some people these days saying "I only want USB C chargeable devices so I don't need so many cables.". Maybe a couple both get USB C chargeable phones instead of one USB C chargeable and one Apple Lightning. There are probably a lot of examples out there (cordless power tool lines, Tires/rims, ball hitches) when you think about it. It seems to make good sense to try to standardize on some of these things such that you need to minimize your inventory of other varieties of the same thing. 

That being said, I can also see folks making a nearly opposite argument, such as with the shotgun example where some folks might say "I'd like to have one of each different gauge of shotgun so I can use whatever ammo I can get my hands on" or similar. This can make sense too. It's up to you to evaluate what you want to do, but at least think about it, and be deliberate of what choice you make.