Trivia: In the fifth episode of the first season, Donna is left alone to babysit her little sister Tina. Both Tina and Valerie, Donna's older sister, were written off the show, much the same way as Richie's older brother Chuck, on Happy Days, or Laura's younger sister Judy, on Family Matters.
Trivia: During Bob's 'open for business' daydream, the man who has his hand up cupped over his ear while he says, "Now, if you'll excuse me, I'm next," is Gary Owens, who played the Announcer on the 60s-70s TV show 'Rowan and Martin's Laugh-In' and always had his hand cupped over his ear. In a few other episodes we only hear his very distinct voice.
Chosen answer: He isn't. Time moves slowly in the show because they didn't want it to turn into "That '80's Show". In the first episode, he say's he's 17 but the second episode was his 17th birthday so he must have been 16. The first 12 episodes are set in 1976, the next 2 seasons are set in 1977, the next 3 seasons are set in 1978, and the remaining shows take place in 1979 with the final show on Dec 31, 1979 when Eric must be 20 as he turned 17 in 1976.
Myridon