I know when i had my earliest memory of a panic situation. I don't know why it happened. My mom left to pick my brother up from school, as she'd done every day. (I was like, 6 years old) and for whatever reason I freaked the hell out about 10 minutes after that, to the point that i cried and called the police.
Something clearly triggered it. But I sure as hell don' tknow what. istill don't know what.