Are you shy?

How funny some shelties pick up some tricks very fast and some very slow. Sing is a fast learner but I was struggling to teach him SHY/SHAMED. It normally takes me less than a minute to teach him a new trick but with this Shy business, it is never easy. I keep asking him every now and then "Are you shy?", sometimes he does it and most of the times he does not! I wonder if he tries to tell me "I am not SHY, mummy!".

For the same trick, Saturn picks it up almost straightaway! Ah! Shelties!!