I agree. Let me provide the context.
Growing up has nothing to do with age. I am glad you feel that you are grown up, I often don't, although I am older in age than you. Please watch this video below, I have no idea, how I remembered this and how I found it!
This is a kid cooking fried rice for his little brother. I think I can say, perhaps I have things to learn from his skill and his compassion. Especially how he tried to keep her little brother engaged and how he gave him the first spoon of rice as it was done. I think I can learn multiple growing up skills from this video, that I probably don't have, or I at least haven't mastered it.
Having to deal with your life and your work without getting help from others is part of 'growing up'. That is a skill often overlooked. I have seen many adults lack this particular skill. I have seen people complain that they don't have a well paid job, and say the government is to blame. I have seen students complain that they are not getting top notch education at current age, and their educational system and ministry is to blame. I feel all these cases can use a little bit of 'growing up skills'.
Not to mention navigate hive ecosystem on their own without any help from anyone.