It is almost like a secret code, understood only by people who have been on this magical continent with its incredible nature and strong energy. The continent is called Africa and the secret thing they are talking about is called the "Africa virus".
When people came home from their trip they noticed that they felt incredibly energetic and kept looking at their photos again and again and that was the moment they realized they have it, the "Africa virus".
It is a serious matter, because now they want to go back, back to the source of this beauty and strength, but they sit at home, the lights are switched on, maybe the heating is buzzing and yet they still feel that strong energy they brought with them. For how long will it last? Well, lets look at the photos again. They make an album or a photo book and its great, because every image carries a bit of this beautiful energy and by looking at it they are again there. They print some of the images and hang them on the wall. Good, that feels better.
And yet, it keeps nagging until they finally make the booking and then it fades away, they are going back. Now everything is easy going and eventually they stand again in the bush or sit in a jeep and the leopard is looking at them with dreamy eyes, well yes, that's what they came back for.
Caution! This is non-fiction!