Actually, Lilith's point is, I think, more important than the readability of a program.
If you end up working on a number of projects, you will probably write over time small functions and libraries of functions to automate simple tasks to save re-writing code all the time. If you have these in their own files, it will definately make it easier to take them between projects without alot of copying and pasting, it would also allow you to have a central library that you could include into your programs, so any changes made to it while your working on one project, can be reflected in any other project it is used in without manually copying and pasting bits and pieces.
EDIT : A simple example of this is a function to return an unused object ID. You could have that function re-written in every project that you work on, or you could have it in a single file on its own and include it into each of your projects, saving having to re-write it every time, and allowing you to improve it from one project and have the improved code reflected in all the projects that include it.
If it ain't broke.... DONT FIX IT !!!