"What's that key for?"

my father asks as he hands my little bunch of keys back to me. He has just been pumping up my tricycle tyres. It is a job I am perfectly able to do for myself but he insists that it is his job - so I let him. It is important to make 87yr old males feel that they are still in charge around the house.
I look at the key he is holding between his fingers. It is a temporary visitor to my little bunch, rather larger than the others. I do not carry a lot of keys with me.
"David's letter box key," I tell him. Right. "He must trust you too," my father remarks.
I suppose David does - not that he has much choice if he wants his letter box emptied in his extended absence. The letter box key, unlike other keys, must not be left in a hiding place somewhere outside a house or I would not be carrying it with my keys.
Other keys are left in hiding places for me. It is still winter here. Some of the oldies have gone north, far north. They have mostly gone to Queensland. The weather is much warmer there. They hook up their caravans and leave at the beginning of winter. They come back twelve or fourteen weeks later - unless they have grandchildren to care for and must remain here. In their absence I know where their keys are. They stop the paper deliveries and get mail forwarded. Indoor plants will be given to neighbours. Cats will be placed in holiday homes for cats or cared for by neighbours. (Dogs go with them.) I tell them I do not need to know where their spare keys are kept but they tell me anyway.
"You might need to get inside the house," they tell me. I always hope I will never need to do so. There was one occasion on which someone left their reading glasses behind. Please could I post them up? I asked where they were and their owner admitted he had no idea. I let myself in to his home reluctantly. It feels very strange going into a house when the owner is not there. Fortunately for me the glasses were in full view on the kitchen table - and I had let myself in through the back door. Underneath the glasses was an unfilled prescription so I included that as well - much to the relief of the owner.
Most of the keys I know about are in fairly obvious hiding places. I have tried to dissuade people from leaving keys under potplants or mats at the front door or back door. That is just too obvious but there are other likely places and many people still seem to think that these places will do.
One of the oldies from around the corner moved into a retirement village recently. The new owner stopped me yesterday and said, "Mr O said that you know where the spare key for the little shed is. He can't remember and I can't get in. I don't want to break the lock."
I told the new owner where the key was. He nodded.
"Sounds like a reasonable place. I think I might leave it there."
"I will know where it is then," I told him.
"So you will but Mr O trusted you and you know where the keys are for them and them," he says jerking his hands in the direction of the neighbours, "And that reminds me. We will be away this coming weekend. I had better tell you where the key is."
I would really rather not know but I say nothing.