Eighteen years ago today (Dec. 11) was a big day for Brad Paisley: It was on this day in 1999 that the singer earned his first No. 1 hit with the song "He Didn't Have to Be," from his debut album, Who Needs Pictures.

Paisley co-wrote "He Didn't Have to Be" with his longtime friend and frequent co-writer, Kelley Lovelace. The tune was based on true events from Lovelace's life: The tunesmith became a stepdad to son McCain Merren when he married his wife, Karen.

""He Didn’t Have to Be" was probably the most life-changing three minutes that I’ve ever written because I really believe we wouldn’t be sitting here anymore talking,” Paisley says of the tune. “Maybe we’d be sitting here with me having written a No. 1 song for somebody else, but I don’t think I’d still have a record deal without that song. It broke the ice for me with radio. It was like you could see potential in it, and that’s an important thing."

Arista Nashville

"He Didn't Have to Be" touched an emotional chord with people all over the country and helped Who Needs Pictures sell more than one million copies.

"I was really lucky; it wasn't like we knew what we were doing," Paisley adds. "I just happened [to write] that with my best friend from the bottom of my heart about his situation.”

The West Virginia native likes the song so much that he also included it on both his 2009 album Playlist: The Very Best of Brad Paisley and his 2010 Hits Alive record.

"He Didn't Have to Be" was the start of a successful streak for the singer-songwriter: Paisley has gone on to earn 19 more No. 1 hits and sell in excess of 13 million records.

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