At this point, it would seem to be less of 'how much', but how much is connected.

There are many things that come to mind...I have even remembered, vividly, three different conditions under which I could have come into this condition! [he adds, frowning.] ...But I...

...But I can't think of which one is real. Or even how all three could exist for that matter!

[Hahhhh.] ...I do remember, however...travelling to different places...