The 42-year-old used to date the group's bassist and she was so besotted with him that she was convinced he was the man she was going to end up with forever, reported Contactmusic.
"That first love you have is so huge and it was, like, so overwhelming and I remember defining myself by that. Basically I was so inspired by this love there was just nothing else," said Stefani, who wrote No Doubt's smash hit 'Don't Speak' about their split.
"I wanted to get married, I wanted to have babies. It was such a short dream, you know what I mean? I didn't realise at the time there is so much more out there," she said.
Stefani, who now has two sons, Kingston, six, and four-year-old Zuma, with her rocker husband Gavin Rossdale, is now glad Tony dumped her because it made her the person she is today.
"It unlocked a whole other side of me I didn't even know I had. Ever since then, I don't remember that little girl. She was different. I think that's the thing: discovering I had something I'm passionate about and I think I'm good at. That defines me now, more than just Young Love or whatever," she added.
Spotted: Ajay Devgn and Kajol at an event in Mumbai
Photos: Sonakshi Sinha, Sushant Singh Rajput at Mumbai airport
Pics: Prabhas, Tamannaah Bhatia at 'Baahubali 2' first look launch at MAMI
'Ae Dil Hai Mushkil' photos: Aishwarya, Anushka, Karan get candid at MAMI
Photos: Huma Qureshi, Neha Dhupia and other celebs at MAMI