mid-14c., perplexite, "bewilderment, doubt, uncertainty," from Old French perplexite "confusion, perplexity," from Late Latin perplexitatem (nominative perplexitas), from Latin perplexus "confused, involved, interwoven," from per- "completely" + plexus "entangled," past participle of plectere "to twine" (from suffixed form of PIE root *plek- "to plait"). From 1590s as "something that causes perplexity, an intricate or involved state or confusion."
The intellect of man is forced to choose
perfection of the life, or of the work,
And if it take the second must refuse
A heavenly mansion, raging in the dark.
When all that story's finished, what's the news?
In luck or out the toil has left its mark:
That old perplexity an empty purse,
Or the day's vanity, the night's remorse.
[William Butler Yeats, "The Choice," 1933]