My family called him Mad Tony, in the "mad scientist" sense—picture Steve Wozniak. Very much like Paul Ford's Tom, Mad was a pivotal character in my life. He and my aunt had 7 children, so their house was a natural place for my parents to occasionally kennel me.
Mad was an electrical engineer for a defense contractor. One of my favorite family stories involved him and coworkers repurposing a radar antenna to disable the speed detector used by a police officer* to target their morning commute. He was also a source of of the many amazing magnets so important to a young wannabe scientist, and responsible for my family's early adoption of technology such as VCRs and camcorders.
After I attended a summer camp that exposed me to BASIC programming, he let me visit his secret geek room, which was a large closet that he'd whimsically (and quite effectively) hidden behind a bookshelf. I don't believe I spent a large amount of time there, but my memories of being 11 years old are dominated by sessions left alone in an autodidactic trance with his Apple II+ and BYTE magazines, learning how to PEEK and POKE my way into assembly programming on its 6502. I was difficult to extract from that room, except for meals of Italian-American comfort food, which eventually helped convince my parents to invest in a top-of-the-line Apple IIe.
I believe it was for my 12th birthday that he gave me the most world-changing gift of my childhood: an Applied Engineering DataLink modem for that Apple IIe. It was capable of connecting to local BBSes at 1200 baud, faster than I could read!
Mad Tony was not someone I spent a lot of time talking to, and we barely kept in touch. Until I left town, I did occasionally attend his TubaChristmas concerts and the theatre company that he spent decades helping off-, on-, and back-stage. But my memories of Mad are an important part of my identity, and I hope my character benefits from a fraction of his curiosity and humility.
* Said officer was from one of the little municipalities of North St. Louis Country now infamous for their fines-based business models.