why did Albert need a medical certificate so badly?

Albert was really miserable at school and he badly wanted to get out of it. He knew that if he will call his dad to get him out of school, he will refuse. So he came up with an idea and wanted a doctor to certify that he will have a nervous breakdown if he goes to school.  Therefore he desperately wanted Yuri to look for a doctor who could give him a fake medical certificate and help him get rid of school.