What has led you to believe that your level of concern before the fact would in any way influence the effectiveness that would be needed in a defensive weapon?
I'm not addressing "effectiveness", I guess. I'm making a reasoned judgement on probability of needing it.
If I KNOW you're going to kick my front door in and try to kill me with a chainsaw, I want to shoot you with a 12 gauge or .308.
If I'm going to the library at 1 pm in a pleasant neighborhood, that isn't high on my list of possible occurrences. Therefore, I don't prepare by bringing those long guns with me.
If I am getting gas after around 9pm, my radar is probably a bit higher, and I might have a standard centerfire handgun usually. If we change that to after 2am, or in certain neighborhoods, that gets upgraded from "might" to "will".
We all have to assess and implement whatever level of defense we feel we may need, and it does change (at least for me). I don't jog with an AR, I don't go to the beach with a shotgun. I don't respond to strange noises in my garage at 1 am with a .22.
Make sense?
Edit to add- we all assess everything we can, and adjust. A couple years ago, in an area within 20-30 miles of my home, there was a string of disturbing shootings. Rural, pleasant area. About 4-5 guys got killed, in very alarming manner, and with a strange set of circumstances. Older middle age (45-60) white guys, in broad daylight, minding their own business during the day. One was shot trimming his hedges on a Sunday afternoon. One was actively involved in scouting and church stuff, all were middle class and basically decent, respectable citizens. It happened over a period of maybe 2 wks.
Ok, I fit that broad profile and had helped out with scouts when my son was involved. The area it occurred was where the scouts camped in the summer from our area.
So absolutely, I was way more self-aware at that time. I didn't go out that way, and I was more conscious of traffic while I was working in the yard.
They found the shooter and tied things in, and it made sense afterwards.