Where do new memes come from? They come about through variation and combination of old ones - either inside one person's mind, or when memes are passed from person to person. So, for example, the poodle story is concocted out of language that people already know and ideas they already have, put together in new ways. They then remember it and pass it on, and variations occur in the process. And the same is true of inventions, songs, works of art, and scientific theories. The human mind is a rich source of variation. In our thinking we mix up ideas and turn them over to produce new combinations. In our dreams we mix them up even more, with bizarre - and occasionally creative - consequences. Human creativity is a process of variation and recombination.
In thinking about thinking we should remember that not all thoughts are memes. In principle, our immediate perceptions and emotions are not memes because they are ours alone, and we may never pass them on. We may imagine a beautiful scene from memory, or fantasize about sex or food, without using ideas that have been copied from someone else. We may even, in principle, think up a completely new way of doing something without using any memes from anyone else. However, in practice, because we use memes so much, most of our thinking is coloured by them in one way or another. Memes have become the tools with which we think.