This is not a step by step pattern to make this pillow, and I will not explain any knitting or sewing techniques in any detail (there are many really clever people out there who do this much better than I ever could!).
The most important part of the pattern is the chart for xkcd comic 149. In addition I have added a few notes on how to get the correct size, a few different ways to construct the pillow and some alternatives.
If you don’t want to make a pillow, you can of course use the chart for something else!
Any suggestions for improvement are more than welcome!