Some people are born with 'writer's eye', I think - the ability to see the world around them in a different way, and a certain kind of imagination which allows them to take whatever experience they have and turn it into something universal. It's not being able to describe a feeling or emotion accurately, so much as it's getting into the heart of an experience to convey it in its essence.
Not all people with this gift become writers, and not all writers have this gift (they may have other gifts such as brilliant craftsmanship, which make up for it) but you can tell when a writer DOES have it, because when they describe something you really feel as if YOU had experienced that very same emotional/sensation. It's the difference between, say, Tamora Pierce, who writes brilliantly and does loads of research - but never quite gets inside the experience for me despite meticulous description - and Robin McKinley, who seems to write much more intuitively and provides far less concrete detail, but hits you BAM between the eyes with the sense of 'That's right! That's just how it WOULD feel!'.
You may have experience which allows you to describe something in accurate and vivid detail. You may have an amazing gift with words which will allow you to sketch in details with beauty and brevity. These things alone will not necessarily give your writing the visceral quality which it needs to really grab the reader's attention. You have to be able to isolate and emphasize the parts of the experience which are the most vital, and to present them to the reader in a way that makes them feel personal and REAL. Even though your description may not be perfectly accurate or incredibly skillful, if it has that REAL quality it is likely to linger in a reader's mind for far longer...