First, hop up and down and tug on your mama's leg and yell "Butter jelly, butter jelly, butter jelly, mama!" over and over again. She will put you into your high chair. Try to avoid being buckled in because when you're buckled, you can't turn the light switch off and on and off and on and off and on. It's kind of fun to hear Mama yell "Boo! Sit down on your bum and stop that!" If she does buckle you in, you can always bang on the tray until the sandwich arrives.
When Mama puts the sandwich on your plate, take it apart and inspect it to make sure she made it correctly.
Then, give it a lick. Finally, take a bite out of the tip. Do this for each quarter of the sandwich.
After taking bites out of all the corners, scrub the sandwich in your hair. This will make your hair stick up in new and interesting ways. It will also make Mama shriek and yell "No, Boo! I just washed your hair!" Of course, by that time, it will be too late. The jelly will be a sticky mess and the peanut butter will have gunked up good.
Mash them all over your high chair tray and tell Mama "I cleanin', Mama." Watch her put her hands over her eyes and sigh heavily.
Then rub the rest of the crusts all over your hands, paying particular attention to the bits in between your fingers and getting under each and every fingernail. Listen to Mama sob as she gets a washcloth and paper towels.