'In some ways, Ian is blessed with the underanalyzing mind of a goldfish. The troubles associated with deeper thought are replaced with basic instinct and a memory that spans a fraction of a second. He's more reactionary than plotting or planning. He doesn't dwell or ponder at length about anything. Just as he realizes his predicament, it blissfully slips from his mind in time to be rediscovered. He sleeps well because of this; there are no worries, and there is no racing mind.
Alternately, physiologically, the repeated realization of the terror of falling is quite draining on a body. It's the rapid-fire release of adrenaline, the repetitive pokes in his flight response, that stresses the gold-encased nugget of fishy flesh.
"Now, what was I doing? Oh my, I can't breathe. Oh shit, I'm falling off a high-rise! Now . . . what was I doing? Oh my . . ."
Blessed indeed are the thoughtless.'