It's true in a lot of situations. In mine, I think I am.
I used to be this smart and goody goody girl but deep inside I had so much angst. As I went way more through my teens, mas naging bukas ako sa mga opinions ko and became more angsty and sometimes I think I became intellectually bobo

(But no naman ha. I think that because I'm afraid that I'm not as smart as I used to be. But that's a bit stupid

). But you know no one's listening and most of the time, no one notices. It hurts that they only see that thing in you when you've shown so much kindness to them. It can hurt that most of the time, no one listens and even wants to listen. They only hear you, think you're saying this and then they scold you. Among the three siblings, I'm the one who hears the most hurtful things from my parents.
And there are times also na parang your other siblings get more advantages than you. That ticks me off a lot because I'm all about justice and I hate that ako lang yung laging pinapagalitan because I'm not the only one who sins.
But ewan ko kung bakit ganito lang sa bahay but out I get along with a lot of people unlike my siblings who seem to shy away. I know a lot of middle children get that advantage