The speaker keeps insisting that every choice is easy, then admits in the very next line to being "a little indecisive." That clash is the heart of the poem. The choices start out harmless, apples or oranges, pink or blue, but they quickly get heavier: skipping school, smoking, and finally whether to stay with someone, whether to forgive or forget. The refrain never changes, even as the stakes climb, which makes it sound less like confidence and more like a line the speaker repeats to calm themselves down.
The shift near the end is the most striking part. A short line, "yeah you're right," seems to answer someone else, as if another person has been pushing the speaker toward a decision. The final line, "it is an easy choice," then lands flat and ambiguous. It could mean the speaker has given in, or has finally decided. The mood is wry on the surface but quietly tired and uneasy underneath, the sound of someone brushing off something that clearly isn't simple.