 In the 1994 film Forrest Gump , title character Forrest is jogging down the street when a T @-@ shirt salesman approaches him , asking him to put his face on T @-@ shirts as inspiration to people . While the men are jogging , a truck splashes mud into Forrest 's face , and the salesman gives him a yellow shirt to wipe the mud off . Forrest rolls up the shirt and hands it back , saying " have a nice day " . Unrolling the shirt , the man finds a smiley face outlined on it . Thus the film credits Forrest Gump with inventing the Smiley logo and the have a nice day slogan . 
