Acostumar means "to get used to" or "to become accustomed to." It's a common verb, but its usage in this specific lyric is quite poignant and relatable.
In the song, the line "Se eu me acostumar a rir pra não chorar" (If I get used to laughing so I don't cry) captures a universal human experience of masking pain. It's a powerful expression of emotional resilience and vulnerability, making it a memorable and engaging word choice for learners.
Bryan Behr sings the moment right before a goodbye he already knows is unavoidable. He opens by trying to stall time itself — "Vou fazer com que essa noite não acabe" ["I'll make sure this night doesn't end"] — before admitting he still hasn't found the nerve to say the actual words: "Tentar me Despedir" ["Try to say goodbye"]. The chorus turns the fear inward, picturing someone else in her place and bracing for the small talk that follows a breakup: "Se alguém me perguntar como anda você" ["If someone asks me how you're doing"]. By the title line he stops pretending: "E eu bem que me avisei" ["And I did warn myself"] — he saw this coming and let it happen anyway.