At times, it's difficult to believe that the brilliant Sheldon can be so dumb. That was the case in "The Egg Salad Equivalency." To fully enjoy The Big Bang Theory, sometimes it's necessary to suspend disbelief and just go with it and enjoy the humor. This show wouldn't be funny if the characters were 100% believable all the time.

They don't always get it right, but more often than not they do. I've had problems with a few The Big Bang Theory season 6 episodes, but overall it's been an enjoyable season and its 2013 return was a positive sign of what's to come.

The opening was awesome. I've only played Jenga a few times, but a life-size version would be a blast. Dangerous, perhaps, but tons of fun. For a change, we got to see Sheldon and Leonard hanging out together in the apartment. That rarely seems to happen anymore now that the cast as been expanded.

While Sheldon's ignorance about his inappropriate behavior was a tad annoying, the rest of the episode was solid. The show has a tendency to cover a topic in an episode, give us some laughs and never mention it again, but not here. Alex's interest in Leonard was the driving force behind the installment and Sheldon's behavior, plus ... we got to see Raj's dog again. She exists!

Instead of Leonard being jealous of Penny's buff ex-boyfriends, she got a little taste of jealousy when she found out that Alex was hitting on her man. I'm a fan of Leonard and Penny being together and making it. I'd love to see a wedding at some point, though the change in living arrangements would probably be too disruptive to the show, As an end game, I want them to be a committed couple.

With Penny's doubts about the relationship earlier this season, Alex's advances shifted the balance in the relationship. Penny was no longer the only desirable one. My favorite moment was when Penny opened her apartment door and found Leonard playing a cello (Did we know he could play that?) and singing, "I'm sorry Alex hit on me. I had no idea I'm cute." The perfect way to win her back!

And she repaid the gesture by buying some sexy nerd glasses!

Penny: Molecules.
Leonard: Okay. come with me.
Penny: Where are we going?
Leonard: To my bedroom. So, I can take everything off but those glasses. And, maybe the boots. | permalink

Oh la la! This bump in the road provided some laughs, but even more important for fans of the show, it further solidified their love for each other.

The Sheldon sexual harassment stuff had its moments, but the ovary and menstruating jokes were just a bit much in the end. Don't get me wrong, I laughed, though due to the absurdity of it all. But that sometimes works and it did here.

The moment that made me scratch my head (not literally) and think was Raj's realization that there are no female cereal mascots. Can that really be true? A quick Google search taught me that this is actually quite a popular topic of discussion. I guess it really is a man's world, well, cereal world at least. 

Raj: Not one cereal mascot is a girl. It's a total breakfast sausage fest. | permalink

How can you not love that line?

Did you find Sheldon's ignorance about his behavior believable? Or were you like me and just suspended your disbelief? Or did you just hate it?

Check out some of the best "The Egg Salad Equivalency" quotes and share your favorite moments!

Carla Day is a staff writer for TV Fanatic. Follow her on Twitter and on Google+.