That's what it would take for her character on Grey's Anatomy, Dr. Addison Montgomery, to really connect with audiences.

At least that's how Kate Walsh saw it.

Her role as the estranged spouse of Dr. Derek "McDreamy" Shepherd, was only intended to be short-term.

But Addison took on a life of her own the longer she was on screen.

Initially, neo-natal surgeon Addison was hated by fans who saw her as standing between Meredith and Derek and their true happiness.

But as Addison's story lines evolved, she became one of Grey's Anatomy's most beloved characters. Not shabby.

"They started off writing her like the wicked witch from the east all in black, coming in to clean up. And then they just gradually made her more and more human and took off the scales one by one," Kate Walsh said.

"They do this with everybody in the show. All the characters have a work persona and a personal persona. I think that's just very real, and that it is also very natural that some people would reveal theirs more than others, like the interns that are working 400 hours a week."

The public reaction to Addison has changed from anger over Derek to joy at seeing her in the arms of Dr. Mark Sloan (Eric Dane).

The character is so popular, producers gave her a spin-off series.

Walsh left at the end of Season 3 to begin Private Practice, which viewers have already had a taste of in a previous episode of Grey's Anatomy.

Set in Los Angeles, the show also stars Taye Diggs and Tim Daly.

"Basically, where Grey's Anatomy is sort of people who worked together that become friends, these are all friends that decided to form a private practice," Walsh says.

The actress adds that viewers can expect to see more of the characters' "messy personal lives." We can't wait!

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.