Final answer:
Michael scowls at everyone as a response to his internal emotional state, influenced by anger, fear, and the pressure of societal expectations to appear content. The negative behaviors of others, like Marcus, also impact his decision to express displeasure and resistance through scowling.
Step-by-step explanation:
Michael decides to scowl at everyone because of the complex emotions he is experiencing, which include anger, sadness, and fear, as indicated by the reference to him only having six months to live. Additionally, the environments and interactions he finds himself in suggest that there is an expectation to appear content and smiling; to do otherwise would signal discontent or fear. In this context, Michael's scowl can be seen as a reaction to the forced positivity of his surroundings, the pressure of societal expectations, and his internal emotional turmoil. The presence of individuals like Marcus also causes discomfort and resentment, which contributes to Michael's decision to scowl. Marcus exhibits his own forms of aggression—both physical, as seen when he throws his knife in anger, and passive, as exemplified by his sarcasm and negative behavior towards a server. These illustrations of negativity and conflict might influence Michael's behavior and reaction to his peers. Finally, the overarching theme of grappling with emotions and the influence of interpersonal relationships plays a critical role in understanding why Michael opts for a scowling demeanor. It reflects his struggle with his imminent mortality and the complex layers of human interaction and societal pressures.