Life isn’t always fair, but you don’t always want to know that, especially when you’re young. You also don’t want to let that notion get in the way of fighting injustice wherever you see it. You don’t have to accept your conditions as normal, you can (and should) push for better. Especially when injustice exists within your own family. Sometimes family members play favorites, even when it ends up harming one person. Or maybe they don’t even realize that they’re playing favorites and it just comes out subconsciously. 

Or maybe they do something that they regret and then have the opportunity to rectify later. You never know what drives someone to do what they do, and you probably never will. This is one of the deeply frustrating things about life as a human being. Try as you might, you can never truly live in someone else’s shoes. You can only guess.