A strange thing...

I promised my mother I would make lunch today.  We'd decided not to have a traditional roast dinner, as I don't much like them and I'm not good at cooking them.  When I went down to the kitchen to cook, my mother was making the Christmas cake, and so I couldn't prepare lunch in the little galley kitchen.  I sat at the kitchen table in the adjoining breakfast room, to peel the potatoes and chop onions.

We were chatting away, when one of the plastic storage jars in the cupboard behind me shot out of the cupboard like a bullet from a gun and hit the floor 12 feet away, in the galley kitchen.  I was so stunned I just sat there for a moment. 

I have tried to find a logical and scientific explanation, but have so far failed.  The contents of the storage jar were not under pressure, it was about a tablespoon of plain flour.  In any case, the lid didn't come off, it was still sealed.

My mother does live on a busy road which gets a lot of traffic, including lorries and buses, but I don't see how this could have pushed the jar out of the cupboard.  If the rattling from the road had dislodged the jar, I feel sure it would have just fallen off, not shot across the room.  Other things in the cupboard, including some teetering stacks of tins and packets were not dislodged.

It's certainly a bit odd.