It's important because it tells you what's the best way for you to learn. It helps because you could be a visual learner, or a hands on learner, ect. It lets you know what will help you best retain information. Hope this helped :)
As a student you have probably listened to an abundance of lectures and read even more lesson texts. Have you developed a system to help you organize what you read so you can easily review and prepare for tests? Cornell notes are a certain type of learning style most students use. It can helps in how you perceive thing in real world scenarios, it also influences your decisions.