I explained a little bit of how I got into it in my answer to Anant. But in addition to that, I think it has been an idea in the back of my head for a long time. I have been writing kids science books for a while and explaining different areas of science to people professionally for a while and so it struck me how cool it would be if all of science (or even all of human knowledge) could be laid out as a big web, showing all the subjects and all the connections between them.
Then if you wanted to find out more about a subject you could 'zoom in' and it would give you a more detailed view of a local region, and then you could zoom in more and more. It would be like wikipedia but in picture form. In fact, you could do something really cool with a VR or AR headset and a giant web of knowledge in the room in front of you which would be colourful showing all the clusters of different subjects which you could interact with.
So that is what I'm trying to chip away on with my v...