You land your first advertising job. Now think of missing work two days straight without calling your boss. Think of deciding you just don't want to complete your client's project. Think of no showing a big client meeting. Can you even imagine someone doing that? Sounds silly that I'd even suggest it.
Now switch the word job with school and imagine missing school two days straight without calling your instructor. Or deciding you really don't want to complete an assignment. Or even no showing a mid-term or final. Does that sound just as silly? It should.
Think of school as your first job. Think of your instructor as your boss. Think of your assignments as your client's projects. Got it? That same responsibility expected at work applies in the classroom.
I can't even imagine a creative in my department just not showing up for a big meeting. Or not coming to work without telling anyone. In the same sense, I can't even imagine a student not showing up for a mid-term (sickness & death do not apply). Or being absent without sending a note why. Am I expecting too much? I hope not.
I'd like to think that students who treat school as a dry run learn a sense of discipline and responsibility. The same discipline and responsibility any creative department on earth expects from their employees.