I had had limoncello many times but never different versions side by side. It was easy to notice differences between them. Obviously. What surprised me was an hedonic reaction: I thought two of them (with more complex flavors) were wonderful and one (store-bought) was awful. Both reactions (wonderful and awful) were stronger than usual. In a small way, I’d become a connoisseur. After that, I was happy to buy expensive limoncello (e.g., $26). I no longer bought cheap limoncello ($18).
— Blogger Seth Roberts explains how he became a limoncello connoisseur; read more in The Willat Effect: Side-by-Side Comparisons Create Connoisseurs.