On a sitcom like The Big Bang Theory — where jokes fly fast and character growth moves at a glacial pace — moments of genuine pathos can catch the audience off guard.

Perhaps that's why viewers were so taken aback by Raj's surprisingly candid confession to Penny that he felt unlovable after his break-up with Lucy in the sixth season finale. Of course, they were equally surprised by the revelation that Raj was able to do it without his usual dose of liquid courage.

For Kunal Nayyar, who plays Raj, tapping into the character's emotional core came naturally.

"To be honest, I just didn't have to dig that deep," he says. "I had to get what he was feeling right, but to get there emotionally, I didn't have to go away into a dark hallway and find something dark about this character. It's just, I've played this character. I know how much he's struggled with this condition, and how much he's struggled with trying to find love, so it sort of came very organically."

Raj's ability to talk to Penny sober is a different conversation entirely. From the beginning of the show, he's only been able to converse with the opposite sex while under the influence. (Or, in one memorable instance, when he thought his nonalcoholic beer was the real thing.) Nayyar sees this as the natural progression for a lovesick character who came very close to a relationship.

"I think his bubble burst," he says. "He finally found someone who he had to take care of, as opposed to it being the other way around, and even she rejected him. He finally met this wounded bird that he was going to take care of, and he thought he was in control, and he still lost her."

So what took so long?

"These guys — the guys on the show — they don't have a lot of room for self-growth," Nayyar admits. "They do, but when they change something about themselves, they do it slowly. It takes a lot of time."