That said, he's one of the smartest people I know, and he has a couple of things that allowed him to become fairly successful over time: an entrepreneurial spirit, great work-ethic, and absolute pigheaded determination. To the extent that I have any of those things, I credit my dad's influence, whether it's a genetic thing, or just social influence during my formative years, or both, or whatever.
All through my childhood, my dad made attempt after attempt at starting and running various businesses. From memory I can recall: running a pulpwood truck, cutting down trees and hauling logs to the paper mills; making handmade crab traps; building docks and bulkheads; a shrimping business, selling fresh shrimp to seafood wholesalers; a business running a bush-hog, clearing lots and what-not; a fill-dirt and land grading/levelling business; and probably one or two more that I'm forgetting. In between those, he made a living working back-breaking manual labor jobs, mostly on dredge boats. But after many years, he started a business pouring and finishing concrete... doing foundations, slabs, driveways, etc. And that one finally "caught" and he makes a nice living doing that now. He's at the stage where he has crews working for him, and he just does what we would call "business development" and "prospecting".
Outside of my dad, if I had to cite some influential figures, I think Nicola Tesla would be on the list, as would Elon Musk, Larry Ellison, Linus Torvalds, rms, Kevin Mitnick, Lou Gerstner, Tom Siebel, esr, rtm, and our very own pg. I'd also have to give a nod to my current $DAYJOB boss, acoliver. Oh, and Bob Young, of Red Hat and Lulu fame. I guess Mark Zuckerberg would count as well, even though I'm not a huge Facebook fan. Oh, Larry Page and Sergey Brin from Google, also.