How many of you out there have a friend that comes over and plays rough with your dogs? The friend that comes, sits on the floor and plays with toys, heavy pats, picks up your dogs, spins them on the floor, etc. Perhaps he/she comes over and begins a game of tug with your dog which may or may not be a game you allow your dogs to play? Perhaps it is a child? Or an adult who won't listen to your protests and brushes them off as an over-protective owner?
Many dog owners train their dogs to be calm and collected. While this is a good thing to teach your dog and an important behaviour they should know, if the only thing you teach them is to be calm and collected, it will lead to some issues. The problem with this technique is ... what happens when they are in a situation that gets them excited and playful?? Do you make them be calm? How? What if they don't listen? Do you forget it and let them play? These are important questions to ask.
Some people, me included, believe that it is important to teach your dog how to come down quickly from excitement. The reason is simple - you aren't going to be able to control all the people that come to your house ... there will always be that one person who doesn't listen. Sometimes these people get the dogs excited and play hard with them. Although you can't control every person who walks in the door, you can control the behaviours your dog will exhibit and therefore control the situation in this way. The dogs need to know how to handle this crazy person even if their main handlers don't play that way.
You see a phrase, or command, in herding a lot with "That'll do". The way it works is the dog is working or excited, etc and the way the handler tells the dog that enough is enough is through the use of "That'll do" or "That will do". That command means "stop whatever you're doing and look at me regardless of the emotional state you're in or where you are". This is a helpful command when teaching dogs how to deal with overexcitement.
We use the same concept with our dogs when we are playing with them. They learn that at any time regardless of what they are doing, with the command of "That'll do" or "Enough" they settle immediately.
The only way you can trust your dogs in a situation is to put them in that situation and teach them how to deal with it. You won't be able to prep them for each and every scenario, but you may as well help them along and give them a good foundation. (This is another thing that default behaviours are for.)