Marks is a billionaire investor - Forbes 2012 $1.9 B.
In this book, Marks brings common sense and a life-time of knowledge to those who are serious about investing.
Like most investors I follow, Marks is older than 70. Why older investors? They have been through many market cycles, made their errors (all investors do) and successfully navigated the market. Learning vicariously is essential in investing or you will lose your capital before you learn your lessons.