Knowing how to do something doesn't mean that you necessarily understand it. As far as Guitar playing goes, this isn't a major problem, until you reach a point where you find it difficult to improve quickly, or want to become an expert musician.

Some decades ago, early in his illustrious career, scientist Richard Feynman described this observation during his years teaching physics at MIT - saying that most scientists he met, knew a lot, but not many really understood what they knew.

Somewhat obvious you might think - but the difference between a guitarist who is very good, and one who is really amazing, is usually the depth of knowledge and understanding the expert player has.

For example, you can learn chords just by memorising the shapes on the neck, but it is far more valuable to you as a complete player to understand the theory behind the chord and deconstruct them to figure out why they take that shape - what intervals are used within their construction and which chords can substitute for others.

One of the most common and frustrating things for a lot of players I have taught, is that no matter how hard they have tried, or how many hours they've practised, they struggle to consistently and accurately play fast. This is very often because of subtle technique flaws.

If you've ever ridden a bicycle that has a very slight buckle in one of the wheels, you'll understand that at slow speeds, it is hardly noticeable. But when you go really fast downhill, the bike destabilises completely. In other words, the wheel only has a very slight flaw, and quite difficult to detect - just like your guitar technique it is works OK until you subject it to speed pressure, then the frustrations start.

If you want to be a master guitarist, make sure you understand how to learn and know how to practise.

Good luck!