The idiom "on top of the world" means feeling extremely happy, joyful, or successful. It can also mean being completely overwhelmed or overjoyed by something.

The idiom "snow under" means to work very hard or be extremely busy, often to the point of being overwhelmed or stressed. It can also mean to perform well under pressure or in a difficult situation.

The idiom "out of mind" refers to something that is no longer being thought about or considered, often because it is irrelevant or not important. It can also indicate that someone has forgotten something, either intentionally or unintentionally.

The idiom "ride on a wave" means to experience success or popularity for a short period of time, often resulting from an initial success. It can also mean to go along with something, to follow the trend or be a part of a group or organization.

The idiom "eat like a horse" means to eat large amounts of food very quickly, often without stopping or savoring it. It can also imply a lack of control over one's eating habits.