Both the Hebrew and Greek words for "sin" are archery terms that mean "to miss the mark." In Hebrew it literally meant "to miss the golden center of the target." Cravings and desires cause one to take their eye off the target, as it were, and miss.
Yes, the creation account, Adam, Eve, and the original sin are allegoric stories used to explain things by the Israelites. Being concerned with whether or not it happened is missing the point. That is like seeing some one use their finger to point to a beautiful full moon on a dark night and focus on the person's finger.