Final answer:
Forrest Gump inspired the creation of the Smiley Face t-shirt. This occurred in a fictional scene where Forrest wipes his face on a shirt, leaving a smiley pattern in mud.
Step-by-step explanation:
The iconic 1970's-80's fad object that Forrest Gump inspired someone to create is the Smiley Face t-shirt. In the film 'Forrest Gump', the main character, played by Tom Hanks, inadvertently gives a t-shirt designer the idea for this design after wiping his face with a yellow t-shirt, leaving a smiley face pattern in mud. This scene represents the way the character influenced various cultural moments in the movie's fictional storyline, reflecting both innovation and the widespread appeal of simple, happy imagery during that era.