If one is in a creditable course of study, one should not bother with the question, "Is this relevant to the rest of my life?" Why not?
1. You do not know what the rest of your life will bring. Read Ecclesiastes on that.
2. You are a student (details), not a teacher. Perhaps the teacher (horrors!) knows better what is important in her discipline.
3. Perhaps the books (if books are still used in your course...) are worth reading. Even if they are not worth reading because they are good, you can practice your critical thinking skills on detecting falsehood, illogic, and plan bullshit.
4. Screening things out because of "irrelevance" will likely rob you of much of your education.
5. Even if the material does not directly relate to your vocation, the disciplines of learning will help you be a better person.
6. So there.