Happiness idioms:
1. On cloud nine - very happy and excited
He was on cloud nine when his sister came to visit him.
2. Have a whale of a time - to enjoy yourself very much; to have a fun time
We were having a whale of time, dancing and drinking.
3. Make someone's day - to make someone feel very happy
Her smile made my day
4. Walk on air - to feel extremely happy
After he won the race, he was walking on air
5. Tickled pink - very amused or pleased about something
I was tickled pink to see her picture
6. In seventh heaven - extremely happy
She was in seventh heaven when they praised her cooking.
7. Over the moon - very happy
He is over the moon about/with his new car.
8. On top of the world - extremely happy or proud of something
When I heard the news I was on top of the world.