The always changing
Often Angry
Sky
Reminds me
Of my sister
Who inarguably
Helped shape
My wordview
What if your sister was the Sky and so that any time you'd look at her, she'd be very different?
It means that some days, she'd be so calm, sweet, and sometimes, if you're lucky, even genius. But frequently, she would be more angry and destructive than anything else really can be in your life, destroying anything she wants to, seemingly for no reason. Would you be able to look back and appreciate the genius?
You think you know that she tries her best to be regular and often doesn't remember doing anything wrong, suffering more than anyone else could, from more than she even outwardly shows.
But it's hard to be compassionate because you have in the past, and it never works out great, even though you know that maybe you should and that you're selfish for not wanting to try.
You might have difficulties understanding who she is. It could take you decades to slightly comprehend that she is just what she happens to be that day, depending on the state of the world. Maybe some aspects are pretty familiar from day to day, but are those elements what make a person if everything else changes?
Perhaps you'll find yourself in a loop, thinking about it all over and over, never reaching a new conclusion, only to realize that there is no final conclusion, and it feels like it's not even worth thinking about anymore.
Could you stop yourself from disliking her, especially seeing the problems she still, and maybe will forever cause? But even that, you might realize, is pointless because she's not, maybe unfortunately so, a monster.
You can imagine that it would be difficult to trust people in general, seeing as you wouldn't even be able to trust your sister to be the same person the next time you see her, let alone be reasonable or friendly. You might learn to deal with stress weirdly, conceivably contributing to some general anxiety.
What an easy topic to make "meaningful" art about, though. I'm confident I wouldn't trade in all my art to have grown up without her.