A long search for something that is difficult to find. To do something that is pointless.
To go on a wild goose chase
A person's intentions are judged by what they do rather than what they say
Action Speak Louder Than Words
To go to bed
Hit the hay
When things build up on each other
snowball effect
To stop working or doing something for the day
Call it a day
An issue that is being intentionally ignored or avoided
Elephant in the room
To wish someone good luck in a performance
Break a leg
to get something or say something exactly right
to hit the nail on the head
Something that happens rarely
Once in a blue moon
To take or enjoy the advantages of two different things or circumstances
The best of both worlds
To hear something from a person who definitely knows
Straight from the horse's mouth
Pull yourself together
To get to the point and leave out the details. A brief summary or description
Cut a long story short
When someone is sick
Under the weather
Hard to decide between two choices
Caught between a rock and a hard place
Do not make plans for something that may not happen
Don't count your chickens before they hatch
To understand something that is difficult to comprehend
Wrap your head around something
To deal with a situation or problem when it happens
to take credit for someone else's accomplishment
steal someone's thunder
To understand what is going on well. To be organized.
On the ball
To tell a secret
Let the cat out of the bag
To trick someone
Pull the wool over someone's eyes
To miss an opportunity
Miss the boat
You can always find something positive in a bad situation
Every cloud has a silver lining
Time goes by quickly when you are having fun
Time flies when you are having fun