Why are wild animals like cheetahs, geckos, dolphins, and whales, etc. so calm around humans?

Cheetahs have such a docile nature especially towards us humans and are like really tamed but why is that? Out of all the things i've read, researched and seen with my own two eyes is that cheetahs are very tolerate of us and we don't even have to cower in fear of attack even though we should be cautious at all times towards any "wild" animal regardless of the species but I remember watching big cat diary one time and Simon King was standing right next to a "wild" adult female cheetah and they were face to face without any fear towards one another and the cheetah was actually tolerating him and jumped up on the jeep sitting quietly and peacefully right next to simon but why? and usually when you go to places that contain captive cheetahs you're actually allowed to go in the enclosures with them, their basically like "wild" dolphins on land in a big cat's body lol but why are cheetahs contained with such a docile nature like dolphins and whales matter of fact why do most wild animals tolerate us being in their presents? It's like they love to interact with us....well egyptians have domesticated animals like cheetahs and hyenas and many other "wild" and domesticated animals but why do cheetahs, geckos, bearded dragons, dolphins, and whales, etc. have such a docile nature towards humans?