Further to the water buffalo, yak and various cow thing..
Being able to tell breeds of cows apart at 100 paces is no different from those folks who can recognise a Goldwing by the sound of its motor or someone who can tell an XA Falcon from an XB by the shape of the tail lights. Or, more to the point, how about being able to tell a Volkl from a Rossignol by the split second flash of graphic you get as its owner does a misty flip? Hands up who can tell a misty flip from a pornstar, huh? And there are some people here who could tell you the oxygen to gas ratio of a welding machine (spot my clever techspeak) by looking at the flame. And others that can tell VB from C# at a glance. And, um, what the hell is a convertible security anyway?
My point is, everybody, and I mean everybody has an area of expertise. Mine happens to be cows, sheep and horses. Really useful stuff in my line of work, oh yes. So, um, what's yours?