Coupon Savvy

K, so I've been trying to make an effort to use coupons more and be more fiscally responsible.
Today, trying to be all coupon savvy... I get to the register at Costco, coupons in hand, and before I even get to hand them over with glee -- with over $9 in savings -- the cashier, starts to say something about the coupons. I don't even hear what he says, because at very same moment I look at the coupons that say "VALID FROM AUG 18 - whatever end date" NOOooooo..... I ask with kind eyes, "Could they please work today? Wait, isn't it like a day or two away?" his reply, "Tomorrow. And as the saying goes 'A Day late and a dollar short.'"
I guess I'm going back tomorrow.
Fact: it was my most efficient, fastest, and least crowded Costco Visit - ever. I don't know if I can strike Costco gold like this again... le sigh ...