Anyone who has been told they're wrong about their own experience will recognize what happens here. The poem is a set of short scripts for answering people who try to talk you out of what you saw, think, or feel. Each time, someone pushes back, and the speaker offers a calm, firm reply: "But I did." "That's what you think." "Just listen."
The tone is like advice from a friend who has been through this and wants you to stand up for yourself. There's a quiet anger underneath, especially in the "Ha!" and the line that "should has nothing / to do with it," which brushes off other people's rules about feelings. The replies stay simple, though. The speaker doesn't argue or explain at length, because the point is that you don't owe anyone a defense of your own perceptions.
The mood is steady, defiant, and a little empowering. The last reply, "Just listen," feels like the most important one: what's wanted isn't agreement, only attention.