A personal gift for my mum, so she keeps finding things only the two of us know about

I was seven when we packed everything that fitted into one car and drove away. My mum told me we were going camping. I believed her for about a year, and to be fair the first months really were a bit like camping, because we had two sleeping bags, one lamp and nothing else.

The flat was on the third floor of a grey block. It filled up slowly. First a table somebody gave us, then a sofa, then curtains my mum sewed herself and got slightly wrong, so one of them still hangs lower than the other. Neither of us has ever fixed it.

This autumn I am moving into my own place, three streets away. I wanted to leave her something and I wanted to take the same thing with me, so I ordered the picture twice. One hangs in her bedroom now and one in mine.

In the middle there is an old truck, loaded the way our life was loaded. Our block is up there with the light on in the third floor window, which is our window. On the other side is the hill we used to escape to, with the bench where we ate our sandwiches and my mum always said the view was better than television. The two sleeping bags are rolled up and tied to the roof. The lamp is still there and it still works. My little blue bicycle leans against the wheel, the one I learned to ride on in the car park behind the block. The number plate is the date we started again.

On the side of the truck, in careful letters: We were only camping. It sounds like a joke now, and mostly it is one.

Then there is everything else, and there is a lot of it. Her sunflowers, because she never had a garden so the balcony had to do. The pot that has made Sunday soup since 1998. Mica asleep on the windowsill with her tail hanging down. My diploma rolled up in the cab, because my mum worked nights so that it could exist, and because she was the one who told me which school to go to when I had no idea. The bus ticket from the year I commuted. Two mugs, one chipped. Her reading glasses on top of a crossword she has filled in with a pen, the way she always does.

She keeps finding new things in it. Last week she noticed the crooked curtain and phoned me about it at half past ten at night.

Neither of us is ever going to explain those sleeping bags to anyone.