A simple question, "How are you?", turns into a small struggle for the speaker. They can't honestly say "good," and they can't say "fine," because neither would be true. So they settle on "alright," a word that sounds mild and harmless but does a lot of hiding.
The last lines are the heart of it. Someone once told the speaker that "alright" is what you say when you're not okay. It works like a code: a way of admitting something is wrong without having to explain it. The speaker seems to have taken that advice and made it a habit.
The mood is quiet and tired. There's no dramatic outburst, just short, plain lines that feel guarded and a little lonely. The poem suggests that people often hint at pain in small words, and that anyone listening closely might hear what's really being said. It also leaves you wondering whether anyone ever does.