It happens to every parent. One day, you have a sweet son or daughter who loves to snuggle on the couch and who puts a smile on your face just by walking into the room. The next day, it's as if someone left the door open and let in an alien with a smart mouth and an attitude that, frankly, you could do without. Entering middle school is like stepping onto a different planet--for parent and child alike. It's a planet where peer pressure, social media,...