bag of wisdom; all one's wisdom
Literally a bag containing wisdom; used figuratively for a person or thing that is a source of great knowledge or good ideas.
My grandmother is the fount of wisdom for our family.
This book is truly a bag of wisdom for daily life.
the brains (of a group); the smart one; personal adviser
Refers to a person who is the most knowledgeable or clever member of a group, often relied upon for advice or solutions.
He is the brains of the team and always comes up with good ideas.
When I'm in trouble, she is my personal adviser.
He's the brains of this company.
I rely on her as my go-to source of advice.