Ok, so you have this beer in front of you. It has several flavors that you cannot quite pin-point. Or perhaps several flavors are blending to make it difficult to discern. You like/dis-like this beer because of that one certain flavor, but you can't describe it to someone else...or even yourself.
Chances are your palate is under-developed. No worries, everyone has this at one point in life, and few develop it passed "average". Now, I'm no expert in flavor detection, I'm still developing my palate. Perhaps there's no 'end-game' in palate improvement...an ongoing process. Yet, once you get started, you'll be glad you did.
In truth, we all develop our palates from the time we are born. Flavors are basically sensations that the brain receives from the tongue, nose and throat. Some foods (or objects) have the same chemicals that produce the same sensations. Hence this is why you may taste "skunk" in a beer. We tend to describe flavors/tastes based on what we already know...or what we have tasted before. So, it makes sense to broaden the library of tastes we have, yes? Sounds easy, doesn't it? Well, it is. All you have to do is experience a wider range of foods (meat, cheese, coffee, chocolates, breads, etc) and food combinations, keep aware of what you taste, and repeat. Sure, some of us will be more adept to pick out flavors. It's just the way some people are built. But, you can still develop your own palate. Your flavor sensation library is growing.
So, I encourage you to try new things, foods, drinks, etc. It'll be fun!