We are in the greatest danger of being run over when we have just gotten out of the way of a carriage.
The reason why the musketeers regiment is so important for Porthos is that it is the only family he's ever known. There's an amazing amount of passion and pride for Porthos in being a musketeer. The Fleur De Lis that he wears on his shoulder guard means the world to him. That brotherhood. Fraternity, loyalty, equality - those things are very important to Porthos.