Childhood is a period that is considered safe by everyone. At this time, you can rely on your parents, ask them for help and receive it.
As the years go by, you have to take on more and more things, and everyone understands this. Many people come to terms with the need to become adults, and understand the inevitability of this. What is important is that most people take this calmly. But some may not accept this natural course of things.
Another person may have a real fear of growing up. And it is always caused by very specific reasons.
Responsibility
In adulthood there are more rights, but there are also responsibilities, which also become huge. The individual will need to take on obligations and fulfill them properly.
Only if he doesn't let anyone down, if he shows himself to be responsible, he will have a good reputation. And that is worth a lot.
Fear of failure
Failures happen even in childhood, there are many of them, by the way. The child makes mistakes due to inexperience, but then goes on to study. The parents insure him that he sees.
But in adulthood, he will have to rely only on himself, and the stakes will only grow. Mistakes will already entail certain consequences that may seem threatening.
Fear of loneliness
In childhood, there are always parents, a person gets used to their company, to the fact that he always has someone to talk to. As an adult, he will need to create a family himself, thereby providing himself with someone close.
An individual may be afraid that he will fail in this regard, that he will not be able to build relationships. He will not be in a hurry to grow up.
Social stigma of age
In society, youth is extolled, sometimes even idealized. Mature age is identified with restrictions, with prohibitions.
A person will be afraid of its onset because he will think that he will not be able to have fun the way he did before, that he will not be able to remain a follower of the same style of clothing or something else. All this may not be particularly to his liking, it may make him wary.
Growing up is often most frightening because of these moments. They can cause real fear.