Does playing guitar become natural at some level of expertise, or is that extremely uncommon? Do you always have to do mental calculations and memorize things in advance, or does a moment come when you can play what you want mostly intuitively?
I mean, when I want to sing a song, I don't think "Okay, I think I will take it in C, then sing this and that interval". And if I want to transpose it up or down a step, that doesn't require any mental effort, either. And I can sing / hum along with some song or melody, improvising or following, without thinking about any musical terms. And thinking about physical details, like specific muscle effort or air flow control, rarely if ever enters it.
Is it the same with the guitar for advanced players? Or is it completely different by nature?
There is a related question with some useful replies here: How can I produce any melody on my guitar as effortlessly as I do with my voice? But I wanted to ask about the more general case, not limited to reproducing a single-voice melody you think of.
From my limited experience, I can only report one example. Picking up song chords by ear was unimaginable when I was just starting out. Now, after playing through many songs, I remember some common patterns, and recognize them intuitively. A little theory knowledge also helps. But still it all takes a lot of trial and error, and occasionally some calculations. I cannot imagine doing this in real time, for example, to play along to a new song. Does it get much better with more knowledge and skill?