Pharmacology is a strange subject. Sudden overexposure to this subject creates a chaos and produces long lasting disinterest. That is the reason why pharmacology is always blamed as a subject for 'memory exercise'. Memory is an essential tool in learning pharmacology. But unfortunately human brain has limited number of neurons. They definitely are not sufficient if one decides to depend only on memory. The primary motive behind writing this book is to reduce contribution of memory while learning pharmacology. Conceptual clarity creates interest and interesting things are easily remembered.