I've always loved his lockpicking business card: https://www.mitnicksecurity.com/kevin-mitnicks-famous-lockpi...
While I assume this is real, part of me does feel like a combination of how young he is and who is is leads me to be slightly skeptical. Assuming it's real, hopefully he would have appreciated the skepticism.
I might not be up to speed with a particular instance of that in his life though. Perhaps that's where my lack of understanding stems from.