Let me focus on two key themes: (1) Fundamentally this is a maturation story, the saga of Amy 'growing up'. She starts off with a rather adolescent view of life, specifically romance, wherein she believes partying and sleeping around is a-okay. Her first V.O. narration states that quite clearly: "Hey guys, I’m Amy. Don’t judge me fuckers. I’m just a sexual girl. I am fine. I am in control." My sense is that it's like Amy is the last one at the party and doesn't want to leave. It's fine to have that attitude when you're in your 20s, but in your 30s, it begins to look a bit pathetic (for the record the actress Amy Schumer is 34 years old). Establishing her promiscuous, partying ways creates a baseline for where Amy starts out. Her journey in her eventual relationship with Aaron - who represents maturity - is a stop-start affair, but eventually she dumps her booze, gives away her drugs, gets serious about her writing, and reaches out to Aaron embracing her desire to grow up. (2) What is at work throughout, especially in the setup, is Amy's ability to fool herself. She is living an illusion, hence the irony of the title: Trainwreck. At the beginning, she certainly wouldn't see herself as that - "I am fine. I am in control." But my guess is after she and Aaron get married, have a couple of kids, when she's out with friends reflecting back on her Old Ways of Being, she would be the first to admit, "Hey, I was a trainwreck back then." And so, yet another movie wherein a Protagonist begins in a state of Disunity and goes through a metamorphosis process moving toward Unity. It's a popular narrative archetype for countless reasons, a primary one being we WANT to believe we can change, we can move toward Unity. And in the case of Amy's maturation process, we want to feel good about where her character ends up.