at/in the back of one's mind

idiom

: in the part of one's mind where thoughts and memories are kept but that are not usually thought about or not perfectly remembered

Somewhere in the back of my mind I knew I'd met him before.

Examples of at/in the back of one's mind in a Sentence

Recent Examples on the Web

For those residents, including yours truly, the threat of a tropical storm or hurricane lurks in the back of one's mind during the summer months like the dull pain of a past injury. —Eric Berger, Ars Technica, 1 June 2023