Avril Lavigne can look back at 2011 with many high notes, one of them being having her song, 'Girlfriend,' being included in Billboard's list of 1,000 No. 1 songs on the Hot 100 chart.

Lavigne topping the charts with the song is extra sweet, as it's a tune she co-wrote with the famed Dr. Luke for her 'The Best Damn Thing' album, which was released in 2007.

"'Girlfriend' was a really special song," Lavigne tells Billboard. "Luke and I wrote it really, really quick together. The chorus took, like, two minutes, and sometimes I found found that the stuff I write really quickly and don't really think about tends to be the magic -- the magic chorus, the magic verse -- because you're not really thinking about it. It kind of flies and comes together. I love it when all the lyrics comes with the melody, and it sort of happens."

'Girlfriend' peaked at No. 1 on May 5, 2007, knocking Timbaland's 'Give It to Me' out of the top slot. The song marked Lavigne's fifth Top 10 single on the Hot 100 chart, being her best showing single to date.

"Dr. Luke and I [both knew] that song was going to do well," says Lavigne. "It was very exciting working on that song. To know that a song is No. 1 is awesome. To have people buy your records and come to the shows, to be doing interviews, to be on TV ... It's all really cool and exciting. It's a unique lifestyle. This was always my dream as a little girl, to be a singer and a musician and a songwriter. It's really awesome. I'm loving every moment of it."

Watch Avril Lavigne's Interview With Billboard.com