I have put my two kids in swimming lessons. They learn in group of 4-5 kids with an instructor. The instructor generally focuses on one kid at a time. When it the turn of one of the kids to learn from the instructor, the other kids practice.
During their break, one of my kids keeps practicing what they were taught. The other one has fun by splashing water on the others. You can guess that one is progressing in their swimming the other one is not.
But one cannot blame one of the kids. Its just how they are built. One of them wants to learn, the other wants to play. Guru Nanak says "Some are near, others are far; only the ultimate judge can pass a judgement."
One who learns and practices with an open heart, sings sweeter.