Thanks caseworker, just what I needed. I always feel better when I smile.
A couple of weeks ago we couldn't get our new front door to lock. We were so cross with the people that fitted it and they couldn't get round until the next day so we slept all night with an unlocked door with furniture pushed up against it. Next day, before they came to fix it, my littlest son asked why the door wasn't locked, then opened it, found a switch that puts the door on/off the latch and said 'this is how you fix it' - he's 3 - he had put the latch on when I wasn't looking.