Is there any example of actor's performances changing over episodes/seasons?

Spoilers for the entire season

The Office is my favorite show, although I do recognize the flaws, and I love to think of the show as a bit of a tragedy sometimes. I like to think the show is about Ryan's transformation and how we is a victim of the corporate world. In the two seasons he doesn't care about his time at dundermifflin, he knows he could disappear. He is still trying though and in season 3 he takes Jim's old job and you see it makes him a lot more mature, and he doesn't like this. He knows he now has to work because he has spent time here and it can't be for waste. His hard work pays off and in the end of season 3 he becomes the new Vice President of Dunder Mifflin. This is one of his biggest changes. This causes him to be incredibly cocky because, well, he was the youngest vp in company history. This causes him to have contempt for many of the people at the Scranton branch because they can make it difficult sometimes for him to succeed yet he yearns for their approval/jealousy when he tells them of all his adventures in the big city. This causes him to do sketchy things such as drugs and committing fraud and lying to the shareholders. After all of this he comes back to the Scranton branch as a temp again and he works but he doesn't give a shit anymore, he doesn't get why he should try. He even asks Kelly for money and pretends to go to Tailand but instead goes to Fort Lauderdale. He is then recruited from a bowling alley to go work with Michael Scott and he then decides he wants go try again, maybe not as hard as before but he wants to do something again. After leaving his job at the bowling alley, michael Scott's company is bought by Dunder Mifflin. Once back there, michael offers him a job there but was joking when it was offered and makes him go back to being a temp. This is his finaly straw and rather than doing any meaningful work he decides to screw it and have fun. From now on he is an annoying art hipster who does whatever he wants. He also spends most of the time either going after Kelly or when he has her then he spends his time cheating on her.

Now Kelly is pretty much the same story. He see Kelly pretty calm in season one and in season 2 she is pretty much the same but more upbeat and talkative. Her downfall is started during the episode The Carpet when Michael doesn't know how to lower Jim's chair while occupying his desk. He then send Ryan back to the Annex where Jim was sitting for that episode. Kelley saw Ryan and instantly became interested and asked jim to ask if he was single/liked him/etc. They start dating and she is obsessed with him. You can tell she loves him but you know he really doesn't care, you could blame some of him not caring on his transformation, and as his transformation becomes worse and worse, Kelley is a victim also as she becomes attached to a monster. A good thing is while she still retains many of her qualities, she starts dating a doctor named Robbie (I think) and they have a really good time together with what seems like a healthy relationship, they even move together to the Unibersity of Miami after becoming engaged. Unfortunately it seems like her destructive behaviors were only latent because when she sees Ryan again at Dwight's wedding they decide to run off together even leaving Ryan's adopted baby.

Sorry if this went off topic a bit, it is just a way I like to look at the office, an American workplace.

/r/television Thread