Tell you something.... I'm not very good at show don't tell. Honestly.
I don't know what it is either but it's almost like I can't wrap my mind around the concept. I've done research on the topic, taken part in blogfests related to it, once held a contest around the idea, and still I struggle to write a story that is shown instead of told. Other people have even given me advice on it.
I try to look at first drafts as write and fix later. But fixing later isn't always easy because it's like how I used to try and fix passive voice on essays, the computer would still say the new way was passive too. Only there isn't a squiggly red line that shows when something is Tell instead of Show. There should be though.
Do you struggle with Tell?