Cereal is like... breakfast soup made out of corn flakes.
Ketchup is like... a smoothie because of the tomato.
Coffee is like... a bean drink energizer.
My life is like... the shoe rack-
Alright listen up, nimrod. This joke is all about comparing food items to other food items. Cereal is soup, ketchup is a smoothie, coffee is an energy drink. But then the author hits you with the punchline: Their life is like a shoe rack, implying it's messy, disorganized, and full of unwanted stuff. You probably have a messy shoe rack too, you heathen.