When the festivities began, people ate chicken. As the festivities wore on, they ate chicken products (eggs). And when January finally came, they ate like chicken, descending upon chicken feed (cereals). Their graph dipped at an alarming rate.
This is a famous meme that tells the story of many spenders over the Christmas holidays. At the beginning, they spend almost all the cash as if they robbed a bank, and with little regard for the coming days.