If you want to read your work ten years from now, you need to save it in a format that future computers can understand. Plain text is the universal file format, understood by humans and most every computer program. Word processor file formats change with the wind but plain text is eternal: it will stay locked at version 1.0 forever.
The best format for storing knowledge persistently is plain text.
The Pragmatic Programmer 1
Unix: the plain text operating system
The Unix operating system was built around plain text. Its system configuration files are all plain text so it’s easier to troubleshoot: configuration files can be stored in a revision control system, so if you make a configuration change that breaks something, a diff on the old and new config files may reveal the culprit.
Unix is famous for being designed around the philosophy of small, sharp tools, each intended to do one thing well. This philosophy is enabled by using a common underlying format – the line-oriented, plain text file.
The Pragmatic Programmer 1
The inputs and outputs of Unix programs are plain text whenever practical, per the Unix philosophy. This allows you to pipe the output of one program into the input of another.
Write programs that do one thing and do it well. Write programs to work together. Write programs to handle text streams, because that is a universal interface.
The Unix Philosophy
Whenever possible use plain text. It’s a simple and robust data storage format. No matter what computer you buy twenty years from now, you can be reasonably confident it will be able to read plain text files.