"I'm a bit of a late bloomer," says the actress, who plays Dr. Addison Montgomery, to the magazine Best Life in its April issue. "I need to do with relationships what I've done with work."
The San Jose, Calif., native, who first appeared on Grey's Anatomy in the closing seconds of Season One, admits she's made some bad choices before.
"In the past, I've been work, work, work â€" and then I'm done and 'cause I'm tired and desperate, I'm like ... YOU!" she says, as though reaching for the nearest male body.
In retrospect, she says she just wasn't ready for the ups and downs of a serious commitment.
"I realize it's a juvenile fear. But I haven't wanted to be in a relationship where I'm doing a downward dog and some guy is just like, 'I hate you. I hate it when you do whatever that thing is that you do that I hate," she said.
But it doesn't help that with her new maturity has come a demanding job playing primetime's most notorious man-eater.
"Here I am working 13, sometimes 16-hour days, and trying to date and it's so new to me to date more than one person. Sometimes I feel like, 'What am I doing? Am I becoming my character, or is my character becoming me?'"
She'd better get used to it.
Her schedule won't slow down if the proposed spinoff series of Grey's Anatomy starring her character is picked up by ABC (the network is planning to test out the show with a special two-hour episode of Grey's Anatomy).
But when Walsh does find her real-life McDreamy, he doesn't need to be as hunky as her onscreen love interests.
"I don't need someone with a hot body. He can be fat or overweight and have a belly. It's very much about style and substance and humor, interest, curiosity and really being smart," Walsh said.