Thank you, that's valuable advice. (Funnily enough, I originally thought that one of the problems may had been in the fact that it was too short to make an impact.)

So in your opinion, it'd have been better if it'd been something like this:

Imagine a graph showing the flow of information from people and events to you. You are at the center of it, surrounded by the brightly glowing information sources you're in direct contact with. They are surrounded by others, each progressive step making them glow less brightly, until finally they're only barely visible against the dark background. Now overlay that graph against maps showing all that is known in the sciences and the arts, and the glow of each node will push back the darkness in that field and reveal to you what is known there.

That network is mirrored by another, the network of the things you know. For as long as you don't forget the things you've learnt, you will retain some connections to the nodes you learnt them from, and of the landscapes around those. As time passes you'll retain the memory of what those landscapes were once like, though if you don't revisit them, not necessarily the way they are now. Below the highly advanced maps of the sciences and the arts are the more basic maps of all the things you mastered as a child. Those are the ones you originally branched out from, and as you expand your currently existing maps, you will branch out to many more still.

...hum. It still needs some work, but you are right - it does seem better.