Don't Bail Your Kid Out
We don't think badly of you if your kid forgets their Friday Folder or library book. Those things are their responsibility. If you come to the rescue, you actually rob them of the opportunity to learn from their mistakes. 

Failure isn't always a bad thing. Kids need to know how to dust themselves off and get back up again after they've messed up. It's better they do it now when consequences (say, a missed recess) are relatively mild.