Slip your mind

Pro Tip 1/3

Accidental Forgetting

Use 'slip your mind' when you unintentionally forget something, not when you choose to ignore it.

I didn't ignore your message; it just slipped my mind.

Pro Tip 2/3

Momentary Lapse

'Slip your mind' often implies a temporary forgetfulness, as if you remembered it before or will remember later.

I knew her birthday last week, but it slipped my mind today.

Pro Tip 3/3

Casual Tone

The phrase has a casual, informal tone, implying a light-hearted or excusable kind of forgetfulness.

Oops, it slipped my mind to bring the snacks.