One of the great battles programmers fight involves synchronization between two different parts of the code. The most common example of this is what the comments say versus what the code really does. Another common example is the structure of data stored somewhere (like a database) and the code that manipulates it.
A lot of the programmer’s effort and technique is devoted to managing, if not preventing, synchronization issues. The rules encouraging encapsulation, or against global objects, have a lot to do with this goal.
The Hard-Core Coder 