Have you ever just sat and wondered about why no one ever refers to Matthew McConaughey as Matt? Well, wonder no more, friends!

Matthew stopped by Jimmy Kimmel Live yesterday, to promote his new film, Gold, and he and Jimmy got to talking about all kinds of things, including the whopping 47 pounds Matthew gained for the film! But when Jimmy attempted to refer to the actor as “Matt”, the conversation shifted to much a more important subject: fear of your mama.

When asked why he never goes by the common nickname, Matthew said:

I was in kindergarten…My buddy Josh Griffin says, “Hey Matt, you want to go play on the monkey bars?” And I ran out and said, “Yeah!” And halfway to the monkey bars I feel this hand on my shoulder—whomp, BAM! Slammed me to the ground. I look up, and it’s my mother in my face, and she’s like, “What are you doing?” I said, “I’m going to play the monkey bars with Josh.” She says, “Who is?” I said, “I am.” She said, “What’s your name?” I said, “Matthew.” She says, “Don’t you ever answer to Matt again. I named you Matthew from the Bible.” I was like, “Yes ma’am!”

Turns out, Matthew’s mom, who also happened to be his kindergarten teacher, choose his name for an important reason, and “Matt” just wasn’t going to cut it!