Colobus monkeys in the forest were throat singing like Tibetan monks. Mist rose from the Kericho tea gardens above us in the gloaming. My son Rider gazed longingly at the water. For a ten-year-old boy obsessed by fishing, patience is impossible. He yearns for that trout with every atom of his being. I was just trying to coach him on the joys of fishing even if one never caught a thing when the clouds above us tore apart with the noise of a B-52 bombing run, followed by rain that came in grenade-sized drops — and then the rod in Rider’s hand quivered and bent down as a rainbow trout hit the fly and stripped out line all the way to the backing. Panic erupted as I barked orders and, realising it was a good fish, tried to grab the rod from Rider’s hands. He fought me off and fought in the fish, which played so heroically it seemed to pull our little boat across the dam’s churning surface. It was dark and we were soaked by the time we landed the fish, all of two pounds, killed him and wrote in the lodge fishing book: Caught on a Black Fritz Gold Head; dusk, tipping down. He will remember that fish all his life and he was electric with happiness.

By contrast, I am like George Orwell’s fat middle-aged hero Bowling in Coming Up for Air, who dreams of the big fish in a pond from his childhood home. As long as the water is still there under the boat I am happy. For Bowling’s pond, it turns out when he revisits the symbol of his hopes and dreams, has been filled in with rubbish and the big fish are long gone. I haven’t brought in a decent trout for a long time. Usually I take Rider and Eve to the Aberdare highlands, where among giant heather and groundsel while dodging elephant and buffalo we cast for little trout in cold alpine streams such as the Chania. Whenever I hook one up, I hand the rod over to the children to bring in. We have also fished on Mount Kenya, staying at the cabins at Rutundu where Prince William proposed to Kate, and the tarns there such as Alice, Ellis and Michaelson are lairs for large and handsome trout.

I’ve poached on an English chalk stream and fished in Devon’s rivers, but nothing matches the wildness of fishing in Africa’s highlands. When I was a boy, my father took us to the Bale Mountains in southern Ethiopia where, on the Danka, the Web and the Shaya, we fished for huge trout in crystal pools that shimmer in my mind’s eye still, like Bowling’s carp pond. While a young Reuters correspondent I used to take girlfriends out to the Gatamaiyu for nookie in the forest after stalking shy trout in shady waterfall pools. And, during the Balkans war, the one time I really connected with the psychotic Serb Chetniks was when I came upon a man tying flies next to a howitzer. He fished in a stream called the Krka, but complained that his fellows killed his sport by tossing in explosives.

On my 48th birthday in Kericho the children went off to stay with their chums from school and Claire urged me to take the chance to row her out on to the large Dimbolil dam. It was a glassy calm evening and Rider and Eve and I had not had any more luck since the rainstorm fish of the evening before. I cast a big fat fly called a Pombe Queen — made by Johnny Onslow in Rongai — and gave the rod to Claire to hold. No danger of a strike there, I thought. We were in the middle of a conversation that married people have in their late forties when the reel came alive with such force it almost smoked. To be sure it was Claire’s fish, but she’s a kind woman and it was my birthday, so she handed the rod over.

It was thrilling. That fish fought with huge style. It went deep — it broke surface and jumped — it stripped out line — it tried to go under the boat. It had amazing strength. When finally he turned his head up exhausted, the Colobus monkeys began their deep Tibetan chant again as if waiting for a death. But having survived some more close brushes this last year, most recently a hail of bullets in a cattle raider’s ambush that riddled my car from so close the muzzle flash sparks bounced off my windscreen, I felt no wish to kill this magnificent animal on my birthday. We scooped him out of the water with the landing net to remove gently the Pombe Queen, admired him for a few seconds and let him swim away. For me it truly was like coming up for air.