Well, if your old-ass self looks at, say, The Jerk, what you’ll notice is a guy who looks 25 but happens to have gray hair. But yeah since I was a kid when that came out he seemed old with his gray hair and all.
I've heard he's a great dude, a terrific musician, and yeah.... what a talent, makes me want to go back and watch Dirty Rotten Scoundrels (first "grown up" film I remember watching) and so many of his other comedy classics. Great Oscars host, too.