One was very old. The youngest is pictured here. The elder was completely unafraid of us. He was literally within touching distance.
What makes the game park experience different than visiting a zoo in North America or Europe is the scale of the habitat* and the unfenced experience. It's kind of like visiting a friend's home. That's a lot different than visiting them in prison. (I'm not saying zoos are bad - they certainly provide an opportunity to see animals in real life that would not otherwise be possible for most people.)
*One of Kenya's game parks is the size of Connecticut.