Depending on how you view Cathy Jamison, she either hit rock bottom on "Happy Birthday, Cancer;" or finally broke free from her unhappy existence.

Those in the former camp might sympathize with this character and her disease, but they also think she's being self-centered by withholding the information about it from her loved ones, while shoving the father of her son out the door just months before these two will need each other more than ever.

Those in the latter camp, conversely, admire Cathy for finally putting herself first. If she's truly happier with Lenny, she shouldn't waste another second of her (abbreviated) life in a relationship that makes her stressed and sad, right?

Of course, things aren't that simple when you're dying of cancer. Cathy wants to have it all: the great sex life, the "good" son, even the happy marriage if she and Paul can work through their issues. However, he seems to be the only one trying.

The show has made Oliver Platt's character a bit of a lush, but can anyone blame Paul for his reaction at the conclusion of this episode? Cathy really did just tell everyone they knew that she hasn't been happy since she met him. Ouch. While Laura Linney's performance continues to make the series enjoyable, it could benefit from some actual decision-making on the part of her character.

That's why I was satisfied with the ending phone call to Lenny. No matter how you view Cathy, we need her to make up her mind here. Give her marriage a try or end it. Tell her loved ones about her cancer or don't. I understand that confusion over how to handle such a diagnosis is completely realistic, but it can also make for frustrating television. The show has been treading water a bit and, like Cathy in her dream pool, I'd like to see it actually swim in one direction or another.

Finally, let's give props to Cynthia Nixon as Cathy's former college roommate. She clearly had a blast playing someone who may have laughed more in this half hour than in the entire run of Sex and the City. With Liam Neeson still on the way, and Idris Elba charming us as Lenny, The Big C has nailed every big casting decision so far.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.