Why would the speaker mention "just" here?

Native speaker’s answer
Rebecca
Here, "just" means "only" or "simply." As if saying that's the <only> thing she wants to do. It's her one request, but the person makes it difficult to do because they don't acknowledge her. Ex: I just want to go to sleep, but the neighbours are being so loud. Ex: Hannah just wants to go to a shop after this, then we can go home.