There is a clear distinction between hearing and listening; hearing requires no effort or attention, listening does.
The same distinction divides drinking and tasting. Drinking is easy; you've been doing it since you were born. Tasting requires close attention to your senses.
Evaluating wine means using your senses of sight, smell, taste and touch. You use your eyes to see and your mouth to touch, but your senses of smell and taste are less obvious.
Read on for a brief explanation of smell and taste. It will make evaluating wine easier.