I'm with what you say generally, but I've often wondered if we CAN learn to see, or is it a gift we either have or don't have?
The rules and guidelines which largely control photography are fairly simple and by no means as complex and interdependent as, say, learning to play a musical instrument. If you've heard the advertisement of a popular language learning program, you've heard the phrase 'learning a second language as you did your first". We understand the human brain is extremely flexible and is at its most malleable stage in our youth and the ability to take in additional learning decreases after we reach a certain age. However, the ability to learn never ceases. We also know older humans who have suffered a serious brain injury (a physical issue) have the ability to restructure the operation of their mind (a cognitive issue).
Whether you are learning a language, a musical instrument or photography, one of the most common mistakes students tend to make is the "I want it all now" matter of instant gratification. I play guitar and when I get on a guitar forum it's quite common to see players of all ages wondering why, after six months of lessons, they can't play like such and such an artist. The advice, of course, is learning to play well takes time. To which the older students often reply, "I don't have that much time left".
A few decades back I was a visiting instructor in an illustration class. I could see which students had a better grasp of the concepts of illustration and which did not before I walked into the classroom. My job was not to teach them how to be an illustrator in my one day in class. My job was to give them some ideas on how I went about the processes of creating an illustration which immediately stood out from the rest. Two specific concepts which always seemed to surprise the students were; 1) have piles of resources from which you can pull and, 2) always be aware of your light source(s). Having resources means you are constantly culling and compiling those images which interest you, which you can analyze for the why and how of that interest and from which you can learn to use similarly inspired techniques in your own work. I would call the task "backwards engineering" of the original, trying to think like the artist to determine how they created their image. In photography you want to think about the technical aspects; F-stops, shutter speed, ISO in particular but also what other elements you can perceive which are making you see the image in a certain way. Most of the students though were unaware of the idea light from one side always casts a shadow on the opposite side. Seems simple enough and a thing we see everyday without really recognizing its importance. However, just as in audio we are most attuned to the sound of the human voice and can recognize abnormalities in a voice more easily than we can in the sound of, say, an automobile tire rolling across a gravel road. Miss the effects of lighting and it will immediately take away from your image. For lighting people this means one thing due to the color of light and for illustrators and photographers this means another since the highlights and shadows will present the opportunity for drama and dynamics.
Back to learning how to play a musical instrument, it is best for anyone learning the basics of a skill to take the learning process in small steps. For the guitarist this might mean learning basic chord shapes and ALWAYS, WITHOUT FAIL playing to the beat. Most aspiring players believe their innate ability to hit on the beat is far better than it actually is. So you slow them down by way of an outside meter, a metronome which does not waver yet can be set to provide any guideline desired. I always tell students to begin practicing at 40 beats per minute which is a very slow tempo but gives them ample opportunity to THINK and be aware of what they are doing and how they should be doing it. Good advice for photographers also IMO. Then take a small portion of what the skill is about and work in that one area for as long as it takes to get yourself familiar with those skills. For a guitar player that may mean drilling the single notes of a Major scale over and over and over for weeks if not months. For the photographer it would mean deciding on one "style" of photography and working very hard at developing the skills required to turn out interesting images in that one style. Bouncing from one shiny bright thing to the next like a crow is fine for those moments when you are allowing your mind to wander and explore. For learning stay with one style, one scale, until you have it down to the point it becomes second nature. And be critical of your own work. A metronome does that for a player and a set time for deliberation, say, a thirty second rule before you can even focus the camera, provides the photographer with the liberties of seeing one subject in many ways.
Anyone can teach themself certain skills at any age if the desire is there. The patient with the brain injury cannot rebuild their mind if they do not have the desire and the will power to work at the rehab. It must be done regularly, not when you feel like it. You must play your guitar daily, not just for three hours on the weekend. Same for a photographer to learn the skills required of their work. Can you teach yourself talent? IMO, no. Talent is somewhat a you have it or you don't thing. However, we all have talent in some area. Possibly your talent it is seeing shapes while another person sees colors. One person can portray motion or emotion or lack of either. You have to recognize your own talent and then build upon those skills which bring it to the front. If your talent is in keeping a steady and forward moving rhythm, you'll be in greater demand than a blazing lead player who has only a few tricks up their sleeve. So don't always think you need "this" talent to succeed. Find your talent and apply your skills to that one area until you feel you have become the best possible at that skill and you'll begin to recognize real talent when it crosses your desk.
Like the musician, work with other people. Learning from others is a great way to test your abilities and to take what others have in their bag of tricks which you can then steal for your own. There's no shame in stealing if you're stealing from the best.