What does that mean to me

"Good manners will open doors that the best education cannot." This phrase sets me thinking that my brain hurts ALOT. But, alas, I found what it means, I think. It means to me that even if you study very hard like 24/7, you still will not be perfect in your studies. You must have GOOD manners to have GOOD grades. The more the GOOD manners you know, the higher the chances of getting GOOD grades.