After an expensive trip to a used bookstore, Dr. Killeen shares why he happily spent more than expected and why he believes books are one of the highest-return investments you’ll ever make. A single idea, lesson, or perspective can transform the way you lead your practice, care for patients, or live your life. Today, Dr. Killeen encourages dentists to think differently about investing in themselves. While it’s easy to spend money on equipment and technology, the greatest long-term returns often come from growing your own knowledge. Books, courses, and mentors don’t cost money as much as they create opportunities that can pay dividends for years to come.