I think part of what makes one lens outings so nice is that you start seeing only photos for that FL. In addition you see more or at least better shots that way. The lens will guide you. I dont think Iāve actally ever really wished I had another lens with me. Particularly when looking at results.
I do feel I have the responsibility to others to make sure I describe things well. This is why I feel the need for several lenses but this is because others have use of my images.
For railway shooting, I canāt afford lens changing due to 1) dust, and 2) close proximity to large moving machinery.
Even for my other subjects, having adjustable reach and framing lets me concentrate on placing the major objects, lines, and textures in the scene.
For kicks, I went to my most recent āscenic walkaboutā collection and did a focal length histogram:
Yep, I could have done that morning with 24mm and 70mm primes, but what doesnāt show here is the interspersal of those shots - in this case, all done without a single lens change. Also, note the intermediate ranges are also represented.
For me, since the '70s and film, a zoom has been first and foremost a composition tool. And that was after working three primes to death, 28mmm 50mm (which got almost no use after I procured the 28mm), and 115mm.
Ha, same here, but at least I hear music the whole timeā¦if only I could write it down 
Every time Iāve seen stats like that they show the vast majority of shots clustered at the edge of the zoom range. The conclusion is often a bit like yours that 24 and 70 primes would be useful or 28 and 105 or 70 and 200 depending on the lens being used.
Part of what I was trying to say above is that itās clearly the other way around. You take 24 and 70mm shots because you have a 24-70 zoom. With a 50mm prime you would take 50mm shots 
In more circumstances than one might imagine this wonāt give you a lesser portfolio at the end.
Iām not arguing that you should use primes as you have clearly explained why for your photography it makes no sense. For say a wedding photographer a 24mm and a 70mm is probably two good focal lengts so a two set zoom would be almost as useful simply because those two FLās are userful in that scenario.
Most of my lenses are primes. But I also have zoom lenses and there are use cases for them escpecially if you are on a boat where you can not zoom by feetā¦
My Zoom lens is a prime 
zooms change field of view, feet change perspective.
Or you have children, who donāt care for the right positionā¦
I donāt think Iāll ever buy a 50mm prime. It just looks too ānormalāā¦ 
Funny, itās the movement of children that got me back to photography. But, that was about point&shoot cameras that took their good time between button-press and shutter-open; by then, children had moved on and we had a nice picture of the floorā¦ 
Bought the D50 to remedy that, and the rest is, well, inevitabilityā¦
The large peaks at the two ends of your histogram could also be interpreted as:
Was that the case?
Pretty much, for that part of the morning. I did go back to the truck and get my 70-300 for a few things I made a note of as I walked about with the 24-70; theyāre not included in the histogram.
I donāt know if this is from being a writer or what, but I always found I produced my best writing when i could literally see the scene in my head and move through it.
But you can do it, because pre-visualization can be done while youāre standing at the scene. Also, I think digital photography has freed us from a lot of the classic Ansel Adams pre-visualization type of work. With black and white (and to a lesser extent color) film, once needed to determine a lot of the artistic decisions before clicking the shutter. When I was shooting b&w film, before I clicked the shutter I had already noted the contrast and development time that the film would need. With digital we donāt need to do that, we need only consider composition, depth of field, and capturing the full tonal range of the scene (via a single frame or bracketing). We can then make way more tonal adjustments in the digital darkroom.
More and more now, since I donāt have the time to spend hours randomly roaming around, I will use the satellite view in google maps, along wit h specific tags on photo sites, and a sun calculator to try and figure out what the scene will look like before I get there. I try to imagine the angle and quality of the light striking the object I want to photograph. I try to figure out a few frames before I ever get there. I guess this counts as pre-visualizatoin.
If you can quantify what you like about your own work, what youāre attracted to, then this kind of feedback loop can help you while youāre out shooting. I donāt know of anyone who has that high of a keeper rate. Mine has improved as Iāve improved my craft, but its still like 1/10 or 1/20 is a keeper.
You can exercise the compositional part of your brain, even if you donāt go out and shoot. Look at othersā work.
For a while I had cut shapes out of paper and would arrange them on the table. If I found something pleasing, iād try to figure out why. Maybe you even take a photo of your arrangement.
I have this, too. The only time I can actually see things in my mind is when Iām just falling asleep. I read somewhere that visualization in dreams happens in a different part of the brain than ānormalā, waking visualization.
Lucky you to have this ability. I love to read but wish I could do this.
I think thatās called āseeingā
Yes ā regular review of my own output and that of others has helped in this regard.
Iāve read a book that discusses composition in this way ā Picture This: How Pictures Work ā itās definitely useful to consider composition in simple ways like this.
What happens if you look at a scene and try to āseeā it in black and white? Or just expose it differently high key, low key? Can you understand the effect of these parameters by looking at a scene with your eyes?
I can do it but itās not stable, takes work and practice and I would hesitate to say that I āseeā it. I guess I sort of do as I understand how it could look but my feeling itās more like a memory. I cant freely focus on everything at once. If i do the whole scene the understanding would be blurry. Doing parts I can get more fidelity. Seems to map well to who we actually process visuals which is different from the complete freeze and evenness of a photograph.
Iām not sure I can even begin to work out how to do this but perhaps itās something that comes with practice (something I usually donāt consistently have time for). I normally do these sorts of things by experimentation in post-processing.
Then I guess we do function differently. It was difficult from this discussion to understand what was semantics and what was actual difference. I have to emphasize though that for me itās very fleeting and hard to āgripā but I can certainly imagine quite well how a scene would look like black and white.
Always very difficult to put into words whatās going on inside a personās head. I have no idea if you see blue the same way I do, for example. Iām still not sure Iām able to explain it well.
Just curious: @elstoc, do you see the scenes vividly when you read? I do, even though (as I mentioned before) I also have problems with the āpre-visualise the final photographā advice.
No. I see no mental images. Perhaps occasionally vague impressions of an overall scene or parts of it if well described. But fleeting and vague as if viewed through a thick fog (for want of a better description). I have trouble calling such impressions āimagesā but I canāt find a better way to describe.
Thereās a Vividness of Mental Imagery questionnaire that has a 1-5 scale from ālike normal visionā to āno imageā. I suppose Iām probably 4-5 on most questions.
I score higher on things Iāve photographed and heavily edited.