He'srenownedas thefountof allknowledgeon thedisease.
Iknowabitabout wildflowers but Icertainlydon'tregardmyself as thefountof allwisdomon thesubject.
Ask Eddie - he's thefountof allbirdknowledge.
You shouldaskMrBrownup theroadwhat to do. He's afountof allwisdom.
Hettie is thefriendliestpersonin theofficeand also thefountof allgossip.