Sleeping in a Made Bed

You know the expression, "You've made your bed, now lie in it"? I think it is used to mean, you did something wrong, now you are getting what you deserve. But I'm not sure that this analogy works. What is the bad thing we did? Making the bed? And then we get to lie down in a nicely made bed. Why is that a punishment? I think we should change the expression to: "You didn't make your bed, now you have to sleep on the uncomfortable sofa." Now, that's getting what you deserve.