When you've taken a container out of the fridge and dispensed its contents into another vessel, return the container to the fridge. Unless the container is now empty, in which case put it in the appropriate recycling/disposal receptacle.
Do the same with tins and cereal boxes taken out of cupboards.
And when you've finished with a drinking vessel/plate, clean it, dry it and put it back where it came from. (If there isn't a place for it, make one!)
Books, magazines, writing implements, remote control units... none of them put themselves back either. It's your job.
It's not a difficult concept to grasp. It's not a difficult habit to cultivate. But most people don't do it, resulting in a cluttered house, hours wasted searching for stuff and (eventually) extended tidying sessions.
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