Acne, commonly called pimples, occurs during the acme of life, in other words the best or peak years of life.95% of all people develop some acne between the ages of 15 and 35.It can begin earlier than 15 years of age or last later than 35. Once acne begins, it runs its own course spanning a period 4 to 10 years or more and then pimples will cease to appear.