Y'know zollybosher, if you're going to quote someone, especially abusing it out of context as a pejorative, it's just basic courtesy and decency to quote contextually verbatim.

Nobody in this entire thread said "yeah (implied generalisation, "it's a") no brainer". Nope, no-one. What was actually said was this, in reply with considered detailed elaboration to your very specific question, and only after several prior attempts to assist you.

You said, and I quote:

"Can anyone advise how they approach this chord or have mastered it."

What was actually written, by me unambigiously in direct response to that sentence within the context of a fuller empathetic reply was:

Begin quote.

"I sense your frustration and wish I could offer some simple solution, but Cmaj was a no brainer for me. The only thing I did to "master" it as such, was finesse the order of placement, the pragmatic perpendiculatrity of my tips, for want of a better word, and curl of the fingers to ensure clean fingering, and smooth changes to and from other chords. Most of that came through awareness generally as I was playing songs, and just repetition playing songs focussing on those aspects during the riff progressions.

I can't recall off hand, but did you mention in a much earlier post that you have either arthritis or a hand injury in your fretting hand? If so, do you suspect this is affecting your flexibility or co-ordination?"

End quote.

Within its own context of a direct answer to your question specific to me as one of your referenced "they", it was part of a wider series of prior posts trying to assist you, even offering you the face saving out by way of inquiring whether you had some encumbering injury.

Over the course of my lengthy very active recreational and professional life, I've casually assisted as well as from formal accredited appointment taught people in training from ab initio through advanced levels to do all kinds of tactile skills required of vocational pursuits from basic officer cadet recruit through graduation as an infantry officer, becoming a pilot at private to consolidating skills at the highest professional levels, recreational gliding, R/C flying, and riding motorcycles - a passion of mine for over 45 years, along with numerous other pursuits. In the course of this, I've observed within every other course, there's a square-gating 'Gomer' who shouldn't ever be handed a live grenade on the practise range, be let even sit on a motorbike, or allowed near the flight controls of anything. You can fail them in the military and vocational courses, but in recreational pursuits, fortunately when it comes to that crux one can just either call time, or say "no" to.

In R/C flying for instance, with very few exceptions, I refused generally to teach people approaching 70 and over. Why? They consistently really struggle with the anticipative mental accuity and acquistion of new motor skills that activity requires to demonstrate they can fly safely, consistently at the rate/speed at which everything is occurring in R/C flight envelope. If/where they are teachable, it ordinarily takes them much longer. Unfortunately, their ego still works much better than the conscious brain or rest of their body, sufficently well enough to set themselves an arbitary parameter in their mind that it should only take "n" hours for them to solo, usually aligned with the minimum rather than average time a boastful agile 20 year old might be touting around the club. When they take longer, or in many cases have left it too late and just can't do it, take a guess who they start to project the blame on and speak derogatively of as part of their personal fight, resignation, flight journey from reality process before they chuck it in?

Fortunately guitar is a safe pursuit. No no-one is going to break bones, potentially lose their life or end up with a bag of sticks with every mistake playing acoustic guitar, the most perceivably perilous thing that could possibly happen is a broken string. But the same learning ..or flight process applies.

I'm older than you, and carrying deficits from neck surgeries affecting my left arm and hand, so your age per se probably isn't your barrier.

Maybe the stated opinion of your previous highly experienced personal tutor you referred to was just, albeit diplomatically phrased, an accurate observation? 😭

The straightforward fact is, that for an overwhelming majority of people learning guitar, it's just not that challenging to play open Cmaj, and it doesn't take them four months to learn to do so, sitting, standing or any other way one might might wish to try it, whether injury or smallish hands encumbered. We've tried to be empathetic and help you only to be churlishly rebuked for the efforts. How exactly do you think that's going to encourage anyone to help you again in future in any way?

It's pretty much up to you now to discover how you're going to play Cmaj if you have the will and persistence through a brutish trial and error 'crash and burn' repeatedly until eventually you 'fly', or not. Alternatively, as previously suggested by me, and now by Christopher, until then you could just substitute with 3rd fret barre form Cmaj instead, arguably one of the easiest barre chords to play which conveniently, is comfortably located within the lower section of the fretboard where the cowboy chords are played.

Cya. 😎