Tim McGraw knows his childhood wasn't an easy time for his mom, Elizabeth "Betty" Ann D'Agostino, and her struggles have stuck with him.

McGraw's mother, now Betty Trimble, became pregnant with him, by future MLB player Tug McGraw, when she was a senior in high school. "She had me young. She didn't get to graduate because I came along," McGraw recalled during a recent media video conference, "and then she went through some terrible things early in my life," he added, alluding to an abusive marriage and the family's struggles with poverty.

His rough childhood showed McGraw "how resilient my mom is and how tough she is and how strong of a woman she is and how well she raised [my two sisters and me] under the circumstances." However, there's one memory of his mother from his childhood that chokes McGraw up.

"For me, it stood out, was plastered in my mind, and for her it was probably one of a hundred times that I didn't see," the country star recalls, "but I can remember ... her working three jobs, probably, just to try to keep the basics in line; I mean, she made no money, really. But I can remember ... walking through the kitchen one night, getting up late, and I was, I don't know how old -- I was, 10, 11, 12 years old, something like that. And she had her head down on the table at, like, two in the morning with bills everywhere."

McGraw pauses as he gets emotional, then continues: "And she was crying, and she didn't see me. I've told her that story before, and she didn't remember 'cause she didn't see me, but, like I said, that, for her, that was probably a hundred different nights I didn't know about." He adds, "That's something that really resonates with me and sticks out with me."

It's a moment McGraw remembers when he hears his new single, "I Called Mama." He hasn't been able to perform the song live for his mom just yet -- in fact, he waited until he knew the song would be a single to share it with her -- but it's earned her approval.

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"I sent it to her and I got -- my mom's gotten better with the phone now, so I got crying emojis," McGraw shares. "I knew better than to call her 'cause I knew what she was doing. I knew she wouldn't be able to talk at the time ... She did exactly what she meant when she sent those emojis."

McGraw didn't write "I Called Mama" -- Lance Miller, Marv Green and Jimmy Yeary did -- but he found a way to honor her beyond its lyrics: "The single art is my mom," McGraw reveals. "It's a picture of her right before she found out she was pregnant with me, actually."

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