Having also not spent that much quality time with the hyperspec, even if I've quite enjoyed dabbling in common lisp from time to time, it wouldn't've occurred to me that the spec would explain 'why' as well as 'what'.
"Underestimating the hyperspec" is a persistent mistake on my part sadly, although I at least seem to underestimate it less these days.
"Underestimating the hyperspec" is a persistent mistake on my part sadly, although I at least seem to underestimate it less these days.