Taylor Swift could have all the friends in the world, but if she had to pick just one, it'd always be her dear old mom. In honor of Mother's Day, Swift tells the story of her song 'The Best Day,' which she says was written as a surprise for her mom, and opens up about leaning on her mother when she had no one else she could count on.

"'The Best Day' is a song that I wrote without telling my mom," Swift reveals, according to her label, Big Machine Records. "I wrote it in the summertime, and I recorded it secretly, too. I had this idea that I wanted to play it for her for Christmas. So, when I got the track I synced up all of these home videos from when I was a little kid to go along with the song like a music video, and played it for her on Christmas Eve and she was crying her eyes out."

The 'Mean' singer -- who has sold over 20 million albums and pocketed prestigious award after award -- also credits her mom, Andrea Swift, for being a best friend when her friends turned their backs on her. "Remembering all the times that we had when she was my only friend when I was 13 and I couldn't understand why my friends were being so mean to me," Swift says, thinking of how special her mother is to her.

"She would just take me on these adventures and we would drive around and go to towns we'd never seen before," Swift continues. "Those adventures and those days of just running away from my problems -- you're not supposed to run away from your problems, but when you're 13 and your friends won't talk to you and they move when you sit down at the lunch table, and your mom lets you run from those problems, I think it's a good thing ... My mom was my escape in a lot of ways."

In other Taylor Swift news, the country sweetie is getting ready to kick off her North American Speak Now tour, which starts on May 27 in Omaha, Neb.

See 'The Best Day' Video Montage Swift Made for Her Mom

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