At first, when I realized that my programs were going into 'outer space', I moved everything named *.pl into a single directory so I would know where everything was. After this, when I needed the program again, I would modify it so thqt it could be called from other Perl programs and do what I needed it to do. After a while, it became evident that I needed to document what was there so I creted a little text document to tell me which program did a particular function for me. This was before I learned POD. :-)
There are better ways to organize what you have... just find the one that works for you.
Mick