The Case of The Missing Sock

My kids lose everything. I have no idea where everything goes, but it's not anywhere I can find it. Crayons, puzzle pieces, game pieces, books, dvd cases, craft project pieces . . . you name it, they've lost it. I doubt I have 1 complete game in my house. I can probably open a crayon store based on what's underneath the sofa. Some days I just don't care and chalk it up to another day in my life. But then other days I get so frustrated. Why are the children so careless? Can't they keep track of anything? The most troublesome part of all this is that they don't seem to care they've lost something. The 4 year old might say, "Oh, the last piece of the puzzle is missing? Oh well. That's ok, mom." No, it's not!! It makes me crazy. Isn't this part of learning responsibility? Clearly, we're going to have a problem in that department.