Following the release of her best-of collection this week on RCA, Dido is officially out of her record contract and a free agent.

“I’m like an overexcited kid,” the British singer/songwriter tells HitFix. “I have so many ideas. ‘I can do this, I can do that.’ I’m like ‘take a breath’.”

More about what’s next for Dido a little later, but first she spent a few minutes looking back with us over her nearly 15-year career covered on “Greatest Hits,” a compilation of all her singles from her 1999 debut, “ No Angel,” on. Among the selections are “Here With Me,” “Thank You,” “White Flag,” “Life for Rent,” and Eminem’s “Stan,” which samples “Thank You,” and helped catapult Dido to stardom.

She listened to the album from start to finish while mastering the project. “It was this crazy, emotional 15-year diary in an hour,” she says. “When you write a song, you’re so clear about where you were and what you were feeling, even more so than when I see a picture. I have such clear memories.”

As often happens, the songs take different meaning and shapes as life progresses. “Everything to Lose,” originally featured on the 2010 “Sex and the City 2” soundtrack, “is probably more relevant now,” Dido says. “When you do finally really fall in love, having a kid, and having the fear” of losing it all.

Indeed, the birth of her son in 2011 has changed the prism through which she views life. “I’m a more emotional person since having Stanley. I was never the big cry person. Now I’ll be in the cinema and I start crying. I was crying at ‘Philomena’ 10 minutes in. My husband was like, ‘Are you alright?’ So any of these songs that are emotional, I feel it all bigger because of Stanley. It opens up a part of you.”

The collection includes a new track, “NYC.” Though written recently, it is about an era, pre-1999, when everything was still possible for her, including failure. “It’s about a time back at the very beginning when I came to New York City with the words of my brother ringing in my head: ‘This is probably not going to happen for you, but good luck’.”

Even after all her success —she’s sold more than 30 million albums worldwide and garnered an Oscar nod for “If I Rise” from “127 Hours”—the uncertainty remains. And she’s fine with that. “I’m still unsure of where the road ahead goes,” she says. “I’ll always be that person. I feel more comfortable not knowing. I crave those feelings. There’s room for magic to happen.”

While being without a record contract would strike fear in some, for Dido, it strikes a sense of possibility where music dictates every decision. “You can just put music out. For me that’s extremely exciting,” she says. “Sometimes [on a label] I feel like you make things and you have to wait for ages and you just play this big waiting game. Now, you can do this project here and that project there. It’s dictated by what you’re doing creatively.”

She’s coy about what’s next as she has material now that is taking her in two “extremely different ways,” and she hasn’t chosen which path to take yet. “It all becomes about the music and that’s the world I live in.”