Brain
Person who thinks of an idea
Brains behind it
Within close distance
A load off my mind
From memory
Off the top of my head
Never occured to me
It never crossed my mind
Trying not to laugh
Keep a straight face
Actions have to effect
Banging my head against a brick wall
Very stressed
At your wits end
Thinking really hard
Racking my brains
Losing Face
Become arrogant after success
go to your head
Tell someone what one thinks of them, especially in anger.
Maintain/help reputation
Save Face
Be alert
Keep your wits about you
Become arrogant after success
Go to your head