For decades, beta-amyloid plaques have dominated Alzheimer's research, but scientists now believe tau tangles are the primary driver of neuron damage and memory loss. This article explains, in easy-to-understand language, how healthy tau proteins support brain cells, what causes them to become tangled, how they spread from neuron to neuron, and why they remain one of Alzheimer's greatest treatment challenges. Drawing from both the latest scientific discoveries and my personal experience after successfully clearing amyloid plaque with Leqembi, this article also explores the promising new therapies that may one day stop tau tangles and change the future of Alzheimer's disease.