See the coding you are practicing if you help an instructor and see that there is still a detail missing.
That anguish happens to me that if I do not learn well that topic I insist until learning however is going to draw more time to learn the other modules, I suggest you continue advancing as on the way you can see the panorm in a macro way and if I remain doubtful in practice it returns to R Epasar, so continue man with his next module.