The most harmful lie that we've all been taught about poetic imagery is that interpreting it is a creative activity. We think we're supposed to think about how the images make us feel and what they remind us of. But when an author uses an image, they usually have some very definite purpose in mind, and it may not be the one we immediately think of. The good news is, correct interpretation is a lot less work than "creative" interpretation. All you have to do is keep your own grubby hands off the text and let it tell you what it means.