I envy you your love for, and expertise in, playing pool. Many years ago I often earned myself a few beers when playing in the local bars of my college town. :) However, I want to point out that your analogies are not exactly parallel. When playing pool, even though your technique and strategies might be varied, your goal is quite straightforward. You need to sink the balls you've called into their pockets. Quite objective. However, when assembling an audio system, your goal (as David pointed out) is very subjective. For example, I tend to listen to a lot of acoustic roots music (blues, folk, bluegrass) and I like a relatively "forward" and intimate sound while maintaining a nice amount of "air" around images. Many of my classical music loving audiophile friends like a much more "removed" sense, as though they're somewhat well back in a symphony hall with good acoustics. So, my perfect sound is quite a bit different than theirs. Find your own sound and move toward it....
As far as actually hearing a difference in sound between components, you will unless you have some kinda substantial physical hearing loss. Many a time an acquaintance of mine has sat in my listening room for the first time saying that they really don't have "good" ears and that they probably won't hear much difference from their car radio, etc. Within a few tunes, their eyes have widened and they are expressing the various aspects of sound that they've never heard before sitting at home or in their cars. It's not a particularly special skill. It's just something to enjoy!