Unfortunately, I can't think of many good things to say about the film.
FOR THOSE WHO THINK YOUNG functions basically as a long, long commercial for Pepsi-Cola. Even the title of the film is the direct quote of a catch phrase used in Pepsi radio and TV commercials of the early 1960s. There are blatant product placements throughout the film, notably a huge Pepsi dispensing machine placed directly in the center of several shots of a night club bar.
The story line is a rip-off of the BEACH PARTY genre, with James Darren doing his best Frankie Avalon imitation, even down to look alike hair style and obviously phony suntan. Poor Pamela Tiffin looks terribly uncomfortable trying to fill the shoes (and swimsuit) of Annette Funicello. To bridge the gap between shots of Pepsi logos, there are the typical "crazed youth" beach activities (tribal-style ritual dances, a bunch of actors grabbing surfboards at the call "Surf's Up!", then paddling out into a perfectly flat ocean, followed by stock footage of real surfers riding huge waves).
There are also several long sequences of comedian Woody Woodbury doing his night club act. The humor in these segments is extremely dated, and falls flat, only serving to bring the story to a grinding halt while on screen. Tina Louise adds some visual spice as an exotic dancer, but Paul Lynde is wasted in the role of a wisecracking musician. Bob Denver plays his typical off-center Gilligan/Maynard G. Krebs character (seemingly the only thing he is capable of).
Darren and Tiffin were also featured together in a companion piece called THE LIVELY SET, a similar but more interesting film with a racing car theme. This film also served to plug Pepsi-Cola, and the cast even featured Joanie Sommers (the manufactured singer who hit the charts with "Johnny Get Angry"), and who provided (coincidentally, no doubt) the singing voice for Pepsi commercials in real life.
Overall, FOR THOSE WHO THINK YOUNG is an curio from a bygone age, contrived and derivative. Any similarity to real life in the pre-flower power, pre-Vietnam era is purely coincidental.
