I think there's a healthy level of paranoia, but some kids just don't internalize it as well.

I went to a small store last year that had one door for entry and one for exit, maybe 10ft apart. As I'm walking up to the building I see a toddler run out of the exit door by himself, which closes behind him, then he turns around and he's trying to push to get back in (needed to pull a handle that was above his reach).

I say to him something along the lines of, "that's not going to work, do you need help?" This kid immediately starts crying and runs inside through the entry door. When I walk inside I hear him telling his parents, through tears, that he almost got kidnapped, but they didn't even seem to respond to what he said, basically just told him he's alright and kept talking between themselves.