The point of learning an instrument, it seems to me, is to be free to do what you like, express what you wish and travel as far in fulfilling that quest as you can.
Obviously there are some hurdles in the way but if you benefit from a proper explanation of some the more abstruse aspects of musicianship and how they might assist you in your quest you're likely to be a lot happier about it. This I try to do.
I have a BA (hons) in Music Performance.
I've been a member of the Registry of Guitar Tutors for nearly 20 years.
The RGT is associated with the London College of Music which is certified by the University of West London.
They have their own syllabus of graded exams.
I'm also familiar with the syllabus of the Associated board of the Royal Schools of Music and the Rockschool grades.
Rather conveniently the subject matter is the same for all of them.
"Simon I shared your pain re your grade 3 Rockschool Guitar exam.
I can't recommend highly enough Richie Burrell as a teacher. He makes it fun, you learn why you are doing what you are doing as well as to how to and he can be anal at making sure you have covered everythingfor the exam.
Finally he got me from being a rank novice to surviving on the stage with some much more talented musicians....
Adult learners can have some concerns about their abilities and may suffer a degree of discomfort at being a novice in a field they have little knowledge of that younger types are untroubled by.
Don't let this stop you.
Difficulties will be overcome in no time and once you realise that music is not some arcane field that only the mysteriously gifted can have access to you'll have a lot of fun.
You don't have to do them.
I strongly suspect that Keith Richards never took one and likely as not nor did Steve Jones of the Sex Pistols.
However you might find them a useful tool to guide and assess your continued progress. Maybe open the doors of Music Colleges too.
I have a thirty year 100% success rate for candidates entering grades on my recommendation.
I can guide your preparation and when I say you're ready to enter you'll pass.