If you are as old as I am then most probably you’ve started programming with a language such as BASIC or a similar unstructured programming language. At that time, an application was just a sequence of lines that defined a sequential logic/behavior via a bunch of GOTO statements that drive the flow by jumping as a kangaroo back and forward between the code lines. Well, in Java, the building blocks of a typical concurrent code are so primitive that the code looks somehow like unstructured programming because is hard to follow and understand what’s going on.