In just four short lines, the speaker reaches a bitter realization: being forced to write with the right hand wasn't random cruelty but a kind of preview. The word "finally" suggests this understanding came late, after years of wondering. Now it makes a painful sort of sense. If the world is built for right-handed people, then training a left-handed child to fit in was an early lesson in how little room there is for difference.
The final lines go further than handedness. Saying a leftie "was never meant to live in this world" turns a small childhood memory into a feeling of not belonging at all. The tone is quiet, resigned, and a little dark, with no shouting or anger on the surface. The speaker seems tired rather than furious. Because the poem is so brief and plain, the sadness lands hard. Left-handedness works here as a stand-in for any way of being that the world pushes you to hide or correct.