It's become very apparent to me lately that I've been taking very much a passive, rather than active, role in my own learning, particularly with regards to engaging with material when I practice.
I'm not just referring to working through patterns or exercises without thinking of the notes involved or the contexts to which they might be applied, but also on the much more basic (and fundamentally important) level of physically playing the guitar. This concept and it's application (or lack of) seems to me to epitomise the problem of things being taken as being 'obvious' - and just because we know something, we don't necessarily apply it as a conscious and consistent part of playing.
I recently took a guitar lesson where the first exercise was to play 10 individual notes, and after playing each one, to rate it from 1-10. It took me a good 10 minutes to grasp what I was being asked to do - play 10 notes, one at a time, anyway you like; loud, soft, dull, bright, muted, with vibrato, maybe bend it, the list goes on... What this exercise pertains to is the translation of what you intend to play, and how close this is to the actual sounds you make when you do play. I found this to be enlightening and scary in equal measure - my average was 8/10. This doesn't sound too bad until you consider we're talking about single notes played one at a time. What this means is that the average note I play on the guitar is only 80% as good as it could be. Scary.
This might seem like a very pedantic and overly-analytical way to look at playing an instrument, but think about it a bit more and it makes sense. Everything else - double stops, chords, flashy solo runs - are made up of single notes. If each note isn't as good as it could be, it stands to reason that neither are any of the above - neither is the rest of your playing, in fact.
I'm not suggesting that for each chord I play, I'm now starting to pick out each note and trying to 'hear' it individually - I don't think I could do that anyway. What it does force me to think about is applying this idea to my playing in a very active and 'aware' manner. Firstly, by consciously assigning a 'purpose' to a note/chord/progression before I play it and attempting to implement the rating exercise until it (hopefully) becomes second nature. Secondly, I'm starting to experiment with different chord voicings, and thinking in terms of what sounds good or appropriate in context versus what is physically convenient to play on the instrument. Clearly the 'best sounding' note or group of notes might not be playable in the time in which you have to play it/them, so you start thinking in terms of which parts of a piece you find most musically important, and to structure your playing around emphasising these parts.
That's taking things from a very basic to a very advanced level, and this whole concept is a life-long part of study rather than something to master in a few weeks or months, but without being aware of it and actively applying it to practice you're never going to be as good as you can be, which is surely the ultimate goal of any musician. It certainly is for me.
I suggest you try the exercise for yourself and you'll see what I mean. Once you've done it a few times - even as a warm-up when you practice - it'll start to become a constant state of mind, and I think you'll feel the benefit pretty quickly, as I am doing.
Combined with the thoughts that will follow this entry, this is now starting to form a much more informed way of playing for me, helping me to think about what I want to play and how I want to play it. I'm still a long way from being able to do this fluently (as improvisation, for instance) but I finally feel I'm taking a few tentative steps in the right direction.