It's not necessarily a waste of time to create a new set of notes with only the important information. In fact, condensing information into a concise set of notes can be a very effective study strategy. This process, often referred to as "active recall" or "summarization," can help reinforce your understanding of the material.
By reviewing and selecting the key points from your existing notes, you're engaging with the information in a meaningful way. This can enhance your comprehension and make it easier to recall during the exam. Additionally, having a set of condensed notes can be a valuable resource for quick review in the days leading up to the exam.
However, it's important to strike a balance. Don't spend too much time creating new notes at the expense of actually reviewing and understanding the material. Focus on the most crucial concepts and information that you need to remember. Consider using techniques like flashcards, self-quizzing, or explaining concepts in your own words to reinforce your learning.
Ultimately, the effectiveness of this approach depends on your individual learning style. Some people find that creating condensed notes is a helpful part of their study routine, while others may prefer different methods. Experiment with different strategies and find what works best for you.