Part of rosemary's popularity came from the wide spread belief that rosemary stimulated and strengthened the memory. In ancient Greece, students would place rosemary sprigs in their hair when studying for their exams. Rosemary contains substances that are useful for stimulating the immune system, increasing circulation, and improving digestion. It also has been shown to increase the blood flow to the head and brain. So the next time you enhance the flavour of some special dish with rosemary, congratulate yourself on a wise and delicious choice!