People often deliberately shorten their long names. Matthew McConaughey is not one of those people. On Tuesday night, McConaughey explained to Jimmy Kimmel why he never goes by "Matt." It was established from an early age by his mother, who also doubled as his kindergarten teacher.

"My friend John says, ‘Hey Matt, wanna go play on the monkey bars?' I say, ‘Yeah,' but halfway to the monkey bars I feel this hand on my shoulder and get slammed to the ground," McConaughey said. "I look up, it's my mother in my face, and she's like, ‘What are you doing?' I said, ‘I'm gonna play on the monkey bars with John.' She says, ‘Who is?' I say, ‘I am.'"McConaughey explained that's when his mom Mary asked him, "What's your name?" After he answered the question, she told him, "Don't you ever answer to Matt again. I named you Matthew from the Bible."

That was that. McConaughey's brother Mike, though, is famously nicknamed "Rooster," so the name rule isn't iron-clad for everyone in the family.

This Story Originally Appeared On Entertainment Weekly