On learning what the traffic signals mean. "Red means stop. Green means go. Yellow means go very fast."
The starman's attempt to smoke a cigarette.
Starman's reaction to dessert. His face scrunches in absolute ecstasy (ooh, sugar!) and it almost in tears with how it tastes.
Similarly, after having sex for the first time (ooh, sugar!), all he does is wear a goofy grin on his face for some time after. Granted, many guys have that reaction after good sex, especially if they're a virgin.