Most people think that lions are the most dangerous animal you could encounter on safari. But basically if you come across lions they are usually sleeping, and completely ignore you. If you're on foot it might be very different. They are often curious around unfenced campsites and it's wise always to keep a lookout, especially at night. But to hear a lion roar nearby, especially at night, is something you don't forget.
I like this piece from a novel by Jonas Jonasson ('The accidental further adventures of the hundred year old man'), which sums up the situation perfectly:
"Lions think logically, and always in the same way. They don't have the ability to tell a living being from its engine-driven vehicle so long as the being has the good sense to remain inside said vehicle. If, for example, an open-cab car full of safari-loving humans arrives, the lion sees a totality, not each individual potential meal. And it thinks three things: 1. Can I eat this? (No, it's too big), 2.. Can it eat me? (No, a long life has taught me that utility vehicles and trucks never attack), 3. Can I mate with it? (No, I don't think I'll ever be that kinky). But when someone leaves the safety of their elephant-sized vehicle, the lion gets very different answers to its questions. 1. Can I eat this? (Yes, and it will be delicious!) 2. Can it eat me? (No, how would that work?) And 3. Can I mate with it? (No, I don't think I'll ever be that kinky)"
The last image - 'lioness stalking' - was taken from the vehicle window. We stopped to watch lions on the track in front of us and were so absorbed we didn't see this lioness on a bank at eye level beside us stalking towards the open car window. The electric window has never closed more slowly!