Where was I?
=what was I saying?
What were we talking about?
I don’t remember.
I have a mind like a sieve.
A sieve= a strainer or colander
I’m a little absentminded.
I’d lose my head if it weren’t attached.(informal)
I’ve lost my train of thought.
train of thought=sequence of thoughts
It’s at the tip of my tongue.
=It is about ready to be said.
It’s on the tip of my tongue.
It’s slipped my mind.
The thought escapes me.
It’s left my head.
What was your name again?
What did you just say?
It went in one ear and out the other.(cliché)
Are we supposed to be someplace right now?