Pardon me, but I see a double negative in your last sentence. For clarification ...

ams6110 · on March 10, 2016

"not non-obvious" isn't quite the same as "obvious." English prose can't be parsed by pure logic alone.

I think in the context of the entire sentence it's clear that the choice of words is correct as written.

krylon · on March 11, 2016

Yes, that is what I meant. Sorry for my convoluted phrasing. ;-) In German, my native language, double negatives cancel each other out.

I mean that in retrospect the idea is obvious, as in, "why did I not think of that".

Of course, in computers and technology there are many, many ideas that appear obvious in retrospect but were still hard to arrive at.