"Ninety-nine percent of the failures come from people who have the habit of making excuses"
This passag is talking about how people for example dont do good on english tests or math tets or any test and than make excuses about why they didnt good on it it is probly becasue they circumvent what they are doing or not focusing on what they are doing and if one minute they are doing their studies and then you look at them they are playing with their x-box or something.