You, and the whole of you, are the only reason why you experience the disease differently from others. your genetic predisposition and your unique response system These are constantly evolving as you grow through life. They are constituted and modified by your upbringing and your experience of different life situations around you Technically the way you are wired and the way you learn and change through life is what makes you unique. This is the main reason why people experience diseases differently. Homeopathy values this uniqueness of yours, and therefore there are no medicines for disease conditions but for the person who is experiencing those disease conditions. This is the basic reason that allows a Homeopathic Doctor to prescribe a single medicine at a given time, even for multiple disease conditions.