Though not necessarily related, it's an example of people who can't do something but know how it needs to be done. I tried for years to play volleyball. Not "backyard" volleyball, but the "real thing". I knew what needed to be done but I just couldn't do it. Call me uncoordinated but I couldn't jump as high as I needed to, couldn't sync with the ball as well as I needed to, and couldn't "finger" the ball as well as I needed to. But, for some reason, I could convey what needed to be done to other people. I could see what they were doing wrong. And I could point it out with suggestions that made the other team members better. Soon, I became coach for our team. Seems like I had a knack for knowing "my" players, knowing weakness on the other team, knowing when someone was "on" and when they were "off". Knew when to change the tempo of the game and which plays to call. They had the talent and I helped them use it. (I can still remember "my" best spiker...he had such power and jumping ability...during one game, he broke the fingers of a would-be blocker! But, the original coach almost cut him from the team). No, we weren't pro or anything, but our team, from a small army base, made it to the East Coast Intramural Army Invitational. Yeah, we didn't win. Finished in the middle (in case anyone is interested). But, I believe my coaching got us there. My way of saying it's quite possible someone knows all about the various aspects of art yet can't draw a stick figure. Is Tigershark a troll? Possibly. But, s/he isn't a troll and isn't necessarily inept at critiquing (sp?) just because s/he doesn't have art to show everyone.