Be/go out of your mind

Pro Tip 1/3

Strong Emotion

Used when feelings are so intense that they're almost unbearable.

I was out of my mind with grief when I lost my pet.

Pro Tip 2/3

Not Literal

It's an expression, not a real loss of mental faculties.

She was out of her mind with excitement - it's just a saying, she was actually fine.

Pro Tip 3/3

Temporary State

Implies a temporary loss of composure, not a permanent state.

When he couldn't find his keys, he was momentarily out of his mind.