When Cheetor was bummed, everyone knew it, even though Cheetor made no special effort to announce his mood - it was like the younger bot just exuded a field of Mope throughout the base. And nothing bummed Cheetor out like getting told off by Optimus.

"You've got to make mistakes before you can learn from them," Rhinox advised him, as gently as he could, but it didn't seem to help - Cheetor only grunted in response and the Mope Field continued unabated.