I have this notebook where I write down only ideas. It's just one of those composition notebooks that you can get anywhere. Some ideas are covered in a few sentences. Some are longer, but never over a page. If I decide to develop an idea I'll start working on it in a different notebook. I've been writing notes in this idea notebook for six years and it's almost full. Most of the time when I am looking through the notebook I'll read the notes I took on an idea and the whole concept will come back into my head, even things that I didn't bother to write down. Sometimes though I will have no recollection of ever having the idea. I've forgotten it so completely it reads like notes taken by somebody else.
This comic came from one of those ideas.
Here is what I wrote in my notebook.
"Meanwhile - A sequence of completely unconnected panels, all with the word 'meanwhile' at the top, all of them dramatic, a cliff hanger (literally), the discovery of a bomb, 'I just don't love you anymore,' 'We're getting a divorce, son.' Etc. Action, love, aliens."
It changed a lot on the way from idea to finished piece.