The Flintstones (1960)

S6E8 Rip Van Flintstone

Feeling uninterested at the company picnic, Fred sneaks off for a nap and wakes up to find himself twenty years in the future. To his surprise, Barney has transformed into the wealthy B.J. Rubble, and Pebbles and Bamm-Bamm are now married. When Fred enters the home of Wilma, who is living on Barney's wealth, he suddenly realizes that it was all just a dream.