well you couldn't fit all of human knowledge in a text file like he claims, not to mention how hard it'd be to give it a proper filename.
Look at the binary representation of pi; you'll find the sum of all human knowledge encoded there in ASCII, EBCDIC or any other code ever invented. You just need Google to index it all for you so it's useful.
And, if you're stuck for 3D video or textures or audio, you can cheat a little and define a 'container' and then use that 'container' within the text file. For example, imagine an XML file containing the rules on how to parse it- that is just another text file. You could do the same with any form of data. Binary data can be represented in ASCII too, they would just be 7x as large as a binary file.