When children begin music lessons, it is often at the 1 of their parents. To many it is just another lesson, no more popular than school. Practice is a bore, theory – difficult, and after a few months some give it up with 2, having learnt virtually nothing. There are plenty of 3, of course, who later make excellent musicians.
With adults it is different. They 4 decide to learn, and are able to learn quickly what they are taught, though this can lead to a feeling of frustration because the physical achievement is slower than the mental.
This is normal. There is no need to 5. Very few people have the natural talent to be a world-famous virtuoso, but almost anyone with the will to succeed can become proficient by dedicated practice.