happy as a clam

Happy as a clam is the expression in which someone is very happy and content. This idiom relates to the fact that a clam looks to be smiling when it is open. If you are happy as a clam, you are constantly smiling and content with your life and the way its going. While happy as a clam is more commonly used for someone who is generally a happy person, it can also describe someones mood during a specific situation.