when (someone) was a (mere) twinkle in (their) father's eye

humorous

at a time before someone was born.

All this happened a very long time ago, when you were a mere twinkle in your father's eye.

• at the bottom of the pile
• at the chalkface
• at the coalface
• at the crack of dawn
• at the cutting edge
• at the double
• at the drop of a hat
• at the eleventh hour
• at the end of the day
• at the expense of
• at the expense of something
• at the hands of
• at the hands of someone
• at the helm
• at the helm of
• at the helm of something
• at the latest
• at the mercy of
• at the mercy of someone
• at the mercy of something
• at the moment
• at the most
• at the outside
• at the point of
• at the point of something