Exaggerated: Bob is always kind and hopeful, even when emperor Evulvz possesses his master prince Harvey, the princess Alice, and his friends and pushes them to ill-threat him. He is certain he will find a solution, despite his lack of knowledge about possession, and the absence of wizards in the county, and also the fact that princess Alice is yet Not Brainwashed, and, in addition, the fact that this curse is supposed to be the most powerful in the country. He is close from becoming The Messiah and The Woobie, being always generous and joyous to the point that you can't help but find him adorable.
Justified: Bob was bread by very depressed but well-meaning people. He knows that cynism is not always the best way to find a solution, but has always believed firmly in their ideals.
Zig Zagged: Bob was kind and cheerful, but then princess Alice, with whom he was in love, sent him on a quest, believed him to be dead and married Prince Harvey. When he returned, he felt depressed, started drinking and quit his job, then decided to regain the control of his life and became cheerful again, asked the princess to give him a job again, was refused, felt sure that she would never like him and became a target to Maddeninto Misanthropy by his guilt over leting alcohool get the best of him and his anger about Harvey and Alice not helping him and joined the Big Bad. He started to develop an unhealthy obsession in the Big Bad's daughter Claire, but was redeemed through the Power of Love, became his former self and saved the knigdom before marrying Claire, and everything became fine despite his remaining but improved drinking pr oble m.
Bob isn't especially kind, nor optimistic, nor cute.
"He is always so kind and so cheerful... don't you sometimes want to punch him ? It must be so hard to take for you..."
"Is it just me, or does anyone else get the impression Bob was a puppy in a previous life?"
Invoked: When Prince Harvey and Princess Alice hire Bob, they learn that he "has a cheerful disposition" by the evil villain who tries to get a hold on them by making them less paranoid.
Exploited: Emperor Evulvz decides to use Bob's optimism and his idealism as a way to send him on endless quests, while he can push Alice to join him for supposedly good purposes she has started to believe in because of Bob.
Defied: "Do you picture me spending my days being all happy and cute and eveything ? People would talk."