instinctive
in-STINK-tivadjMeaning done naturally, without learning or thinking
Memory hook in an INSTANT, no lessons needed. The baby turtles hatch on the beach and, in an instant, head straight for the sea; no one shows them the way: the move is instinctive.
Pulling your hand back from a hot pan is instinctive.
In context No one teaches a spider how to spin its first web; the skill is instinctive, built in from the moment it hatches.
Similar automatic, reflexive, innate, unlearned
Opposite learned, deliberate
From instinct, from Latin instinctus, “an urge, an impulse.”