You're right Phil - the 'excitement' does wear off, but it's replaced by something deeper.
It's an addiction, and a need, for that Arillas fix, firmly based on the sure knowledge that as soon as you step off the plane , and the heat and the combined smell of the diesel and the vegetation hits you, you will give a big sigh and the instant relaxation will just wash over you, more than anywhere else I've ever been ( - and I'm well travelled!).
Suddenly, for an all too brief time, all is well with the world.