Close, somewhat unwittingly.
I buy fresh eggs locally. I was visiting a friend and was in charge of breakfast the Saturday. Bacon and eggs, and he said 'wow, these eggs are good. Fresh?' I laughed and said yes, told him where they are from. Two weeks later, he's at my place. I again serve bacon and eggs...he has his and said "these aren't the fresh ones, are they? He was right, my supplier was out.
I always knew the difference was there, but him being able to pick it out just like that cemented the difference for me. Sure, I knew which were which, but they all got fried!