In 1978, prime-time television got its first "nighttime soap opera". The show was
Dallas, the story of the Ewing family, oil barons in the great state of... you guessed it... Texas.
Prior to Dallas, daytime television was dominated by talk shows, game shows, and "soap operas". Soap operas were heavily serialized stories with lots of drama and sexual innuendo (but not too much -- this was still the 70's). But evening belonged to half-hour sitcoms, one-hour police dramas, both strictly episodic, and movies of the week. To have an evening show that was actually serialized was a breakthrough. To have it be a drama with sexual innuendo was downright scandalous. But the time was right, and Dallas was huge. Since my parents and my girlfriend at the time were both fans, I ended up watching it one way or another.
Patrick Duffy played Bobby, the second-oldest Ewing son, and was tired of being second fiddle to Larry Hagman, the eldest son and basically the star of the show. So he wanted out of the show, and they killed off his character.
The ratings started to tank. Hagman's character, J.R., was awesomely evil and brutal and people loved to hate him, but Duffy was the one the ladies loved (see gif above).
So the first episode of the following season, his widow wakes up and hears someone in the shower. What the...? She goes into the bathroom, and there's Bobby in the shower. He says something like "Oh, sorry I woke you up." Widow/wife is in shock, as is the rest of television-watching America. Bobby is alive. The entire previous season was just a dream. She dreamt the entire season. It never happened. And the show went on from there.