Just to echo Tony's comments earlier about small margins.
We went on a safari in Kenya but my wife was ill in the morning. We spent 30 or 40 minutes with the driver of our little bus trying to persuade us to divert to a hospital. She was having none of it. Random tablets, lots of water and fresh air was her self medication, no way was she going to a Kenyan hospital.
Anyway, that put us way behind the crowds that all mass around whatever animal has been spotted, our driver basically had to go and do his own thing. We sat and watched baby elephants playing for a while. Water buffalo fighting. Wart hogs, cheetah, wild dogs, gazelle type things, just loads n loads of everything. Then we saw lions hunt down and kill an ostrich. Driver said that in 10 years he'd never witnessed that before.
We even had the experience of grounding the bus (I say bus, it was a Bedford Rascal), so the driver was acting as the world's most nervous look out whilst his 6 tourists tried to get it off the tree trunk it had failed to negotiate.
Then, days later, snorkelling with a million fish off a reef in the Indian Ocean.
All a bit **** special.