I have had the distinct pleasure of cupping and sampling JBM Wallingford Estate, Kona, Don Telmo from Mesa de los Santos, Kenya Jungle Estate, Yemen Mocha, Tanzanian Peaberry, Cup Of Excellence winners from Panama, Colombia, Guatemala, Nicaragua, La Magnolia from Minita de Oro in Costa Rica, with a few others thrown in.
It's no different than wine in the sense you develop a taste for certain characteristics and nuances. But you suddenly discover that you can appreciate the difference in each one. For me, JBM and Kona didn't get it, but Kauai Estate was really good.
I thought all Central and South American varietals would be mild, but then I got a taste of a Guatemalan bean with some body to die for! I found that I had to approach each one with an open mind and a ready tongue. There's no such thing as a bad coffee, just coffee you don't resonate with.