Some people are easily influenced.  A therapist or tranquilizers might help save you from this fate:
In the middle of driving down the highway, Homer skids to a halt in front of a billboard.
 Homer: [ gasps ] It must be the first of the month: new billboard day!
         [ a car-carrying truck stops behind him ]
         [ a bunch of cars drive onto it accidentally ]
Driver: Heh heh heh...finders keepers.  [ drives off ]
 Homer: [ reading ] "This year, give her English muffins."  Whatever you say, Mr. Billboard!  [ skids off ]
         [ stops suddenly at another billboard for barbeque sauce ]
         [ cars collide behind him and explode ]
 Homer: [ reading ] "Best in the West."  Heh heh heh, that rhymes!
         [ looking at the next one ] "Clown college"?  You can't eat that.
At the power plant, Homer piles his purchases (including MSG, "Best in the West", and English muffins) at his work station.  "Well, I got everything I was supposed to get.  I'm not going to enroll in that clown college, though...that advertisement had absolutely no effect on me whatsoever.  In his daydream, he imagines himself sleeping and dreaming
of himself eating a sandwich.  The billboard for the clown college batters its way into his thoughts.  The Krustys on the billboard start dancing to circus music.
Lenny walks in: "Hey, Homer: the section you're supposed to be monitoring is on fire."  Through Homer's eyes, Lenny is a dancing clown. Four clowns roll out of a safety door and start dancing sitting down (in actuality, it's Charlie and three other men trying to put out their burning clothes).  Homer chuckles to himself.  "Clowns are funny..."
At dinner that night, Homer scoops a large pile of mashed potatoes onto his plate and shapes it carefully into a circus tent with his fork.
"Mom?"  Lisa asks worriedly.  "I think I'll have some wine," responds Marge. 
Homer looks up to see his family dressed like clowns, holding miniature billboards  advertising the clown college and dancing to circus music. 
"Marge...?" asks Homer slowly.  "Yes, Homey?" answers the clown Marge, starting to hum circus music.
Homer: That's it!  You people have stood in my way long enough.  I'm going to clown college!  [ leaves ]
 Bart: I don't think any of us expected him to say that.