'Perplexed' is Latin for 'thoroughly tangled' — from 'plectere' (to weave). Your thoughts, knotted.
To cause someone to feel completely baffled; to make something more complicated or harder to understand.
From Latin perplexus (entangled, confused, intricate), composed of per- (thoroughly, completely) + plexus (interwoven, braided), past participle of plectere (to weave, to braid, to intertwine), from PIE *pleḱ- (to plait, to weave). To be perplexed is to be thoroughly tangled — the mind's threads so interwoven that one cannot find a way through the labyrinth. The PIE root *pleḱ- has a rich descendant family: Latin plicāre (to fold, whence complicate, explicit, reply, complex), Greek plékein (to weave, whence plexus), Old English fleax (flax — the plant whose fibers are woven), and Germanic *flehtaną (to braid, whence German
The anatomical term 'plexus' (as in 'solar plexus') comes from the same Latin root — a plexus is literally a network of interwoven nerves or vessels. When you are perplexed, your thoughts are as tangled as a nerve plexus. The 'solar plexus' is so named because the radiating nerves resemble the rays of the sun.