to bear something in mind
to remember something important: You must bear in mind that the cost of living is higher in New York."
food for thought
something that makes you think about something deeply
slip my mind
to forget something
lose your train of thought
to forget what you were saying because of an interruption: "Now what was I telling you? I'm afraid I've lost my train of thought."
miles away
unaware of what is happening or what someone is saying
a memory like a sieve
a really bad memory
go in one ear and come out the other
"I keep telling him about the risks but it goes in one ear and out the other. He never listens!"
off the top of your head
not a carefully considered opinion often because of a lack of time to check the accuracy of the information
a trip down memory lane
when people think about and remember things from the past
to jog someone's memory
to help someone remember something: "You don't remember who was with us that day? Here's a photograph to jog your memory."
to rack your brain
to try very hard to remember something
a senior moment
to have a lapse in memory, usually unexpectedly
a blast from the past
a person or thing that reminds you of an earlier time in the past
on the tip of my tongue
a word or name that you can almost remember but not quite - it's just out of reach
have (something) on the brain
If you have something on the brain, you think or talk abut it all constantly. "Stop talking about golf. You've got golf on the brain!"
if my memory serves me well
if I remember correctly, have not forgotten any details
