Why does Kevin Nash lie about where he got the nickname "Big Sexy" from?

He got it from local indie talent Luther Biggs. Nash made a deal with the guy that he got a WCW developmental contract out of it if he let Nash use the nickname.

But Nash ever since then lies about it and claims he came up with the name himself, even though it's easily disprovable because Biggs had the name first, on WCW television. Why does he bother lying about a story that makes him look good to instead come across as a lying asshole instead?

Is he this addicted to lying?