many animals are habituated to humans, they have lost their immediate fear. They see people in land rovers on a daily basis - tourists etc, they are non threatening. Wild animals view the world as things to eat, things to fear and things to ignore.

When their born their parents tell them not to notice humans

I'm watching Big Cat Diary on animal planet, and one of the cheetas just got in the guys keep and he he stood in the rooftop thing and she didn't even notice him. Why during nature documentaries don't wild animals seem to notice that a huge jeep with people in it are around?