To pick up on the subtleties in communication that someone is
purposefully trying to
deliver. To understand the
implied message behind someone's words, gestures, or actions.
Ash needs to take a hint that Misty, May, Dawn,
Iris,
Serena, and a fucking
Latias all want his D. Instead, all he does is train his pokemon so that he can lose his next gym battle (and eventually get the badge without defeating anyone).