How strange it always is, that first waking in the Luangwa Valley, those few minutes between sleeping and doing as the first grey light hits the sky. I was in bed but the life outside would not wait: and as always it was like being home and not recognising a soul, like being back in your own house and unable to find the bathroom.

I knew that sound, I knew that sound – but I didn’t know what it was, and it was a kind of agony. Was this really the Valley, the place where I left a piece of my heart all but 30 years back? And if so, why couldn’t I put a name to the mad cacklers just outside my hut?

I was due to welcome nine clients to the Valley the following day, co-leading a trip with my old friend Chris Breen, and yet I couldn’t remember the voice of a single bird. You is feeling like you was lost in the bush, boy? Words of James Joyce: you nailed it again, Jim.

And then a wild screaming duet: glorious as the Valley itself. I knew, I knew what that one was, but I still couldn’t put a name to it. It was like trying to adjust to the real world after some traumatic injury: the familiar has become alien and all your certainties have dissolved.

Scream again, you screamers: give me another clue, I beg you. And scream they did but I was no closer. Had I really been here before? Had I merely imagined that last trip, eleven months back, when surely I could recognise the sound of every bird that called?

But that one, that rhythmic repeating bit of song: yes, I knew that and now there was solid ground beneath my feet: Heuglin’s robin, irritatingly and confusingly renamed white-browed robin-chat, but either way an old friend of African mornings. I took confidence: that gabbling, why, I hear that at home in Norfolk: it was Egyptian geese, always garrulous birds.