What is "emotional maturity" anyway? Why is maturity a good thing? I don't understand why there is such a stigma against immaturity. Just be who you are and try to be respectful to others. Why are we in such a big hurry to grow up?

I've found that complaining to people about other people within the same social circle almost always leads to drama. It's also not very nice to talk behind people's back. So not doing that is probably a good idea.