If there’s one good thing in this benighted world, it’s that renowned nice guy Henry Winkler is a big star once again. (Not 56 percent of the viewing audience big, but there were only three networks the first time around.) On Tuesday’s show, Jimmy Kimmel brought out some vintage Happy Days memorabilia from Winkler’s long-ago first foray into TV stardom, with the clearly tickled Winkler happily debunking some of the studio-manufactured hobbies chronicled in an all-Fonzie fan magazine. (The Fonz may have liked making birdhouses on the show, but, sadly, Winkler himself was not, as the magazine assured fans with an elaborate potter’s wheel photo layout, an avid ceramics enthusiast.) With Happy Days childhood fan Kimmel quizzing Winkler on the Fonz’s most infamous, lexicon-spawning stunt, the legendarily affable Winkler happily explained that, yes, he did do all of his own waterskiing (apart from the actual jump over a very real, penned-up shark), thanks to his father’s prodding that he tell producer Garry Marshall that waterskiing was an actual skill that could be added to Arthur Fonzarelli’s coolness quiver. (Winkler, ever the mensch, even donned a wetsuit later in the show to take part in Kimmel’s ongoing bellyflop tournament.)