At the back of your mind
Meaning - Something that you are not thinking about right now but is in your thoughts.
Example - At the back of my mind is the fear of failing the test.
Be in two minds
Meaning - Be undecided.
Example - I'm in two minds about what to do.
Bear/keep in mind
Meaning - Remember
Example - Bear in mind that no food will be served on board.
Bring to mind
Meaning - Recall something
Example - Fish and chip shops bring to mind my holidays in Britain.
Broadens the mind
Meaning - Helps you understand more about different subjects, people, ideas and places.
Example - Travelling broadens the mind.
Change your mind
Meaning - Change your decision
Example - I was going to go sailing but I changed my mind when I saw the weather.
Cross your mind
Meaning - Come into your thoughts as a possibility
Example — It crossed my mind that the child might be hungry.
Get something or somebody out of your mind
Meaning - Stop thinking about someone or something
Example - No matter how hard I try I can't get the accident out of my mind.
Give someone a piece of your mind
Meaning - Express your disapproval in a firm or angry manner.
Example - I'm going to give those kids a piece of my mind about the noise they're making.
Go out of your mind
Example - Go crazy or be insane
Meaning - You're going to walk across the desert? Have you gone out of your mind?