My Econ Honours supervisor said to me "You know students get so caught up with regressions and equations when a good graph often really makes a better point"

(As you might gather, I have carried that with me)

Once after an Honours Micro lecture that involved 1 hour of calculus and not one actual word written on the board, I put up my hand and said "So you mean we've just proven that when prices go up, demand goes down?"