Gone but not forgotten

I really don't understand this.

Last year we went on a walking holiday, ten days on the South West Coast Path, and I took my cheque book with me. After we returned I never saw it again.

I existed quite happily for many months without one, until finally I needed to write a cheque (to , in fact). So then I replaced it, and in due course I took the new one with me on this year's walking holiday.

And I haven't seen it since.

I turned the flat upside-down looking for it last night. I excavated the archaeological depths of my desk, looked in pockets of long-forgotten jackets, and even searched the car – all without success. (All I found in the car was a rotten tomato, hidden in a inccessible corner of a door pocket where it had fallen from a plant we were bringing back from the allotment. I found it by plunging my fingers deep into the putrifying heart of it as I groped around in the darkness. When I told about it later she said “oh yes, I knew about that”.)

But tomatos aside, where is the bloody chequebook and what is it about walking holidays that make my financial stuff want to head for the hills?