I think it's actually the last 10 lines of code, not 12. I just wrote these 10 lines:

   Remember A as forty-two
   Tell me about A
   Remember B as A
   Tell me about B
   Remember C as B
   Tell me about C
   Remember D as C
   Tell me about D
   Remember E as D
   Tell me about E

And you can see how it plots the dependencies as a graph on the right, which is kind of neat. But when I add the 11th line:

   Remember F as E

You see the graph being turned into a forest with no dependencies, because it has forgotten the root dependency A. Indeed, if you enter "Tell me about A", it will say it does not remember A.

Another neat thing to try is:

   Remember x as zero
   Remember y as x
   Remember x as y