Well I realized that when my dad was going through some financial difficulties and It dawned on me that I had to pick up the slack and start taking care of my own issues myself and not depending on him for everything.
Honestly it wasn't until I actually started taking care of myself and making my own life choices and financial decisions that it dawned on me that I wasn't a kid anymore. I had real world problems that I had to find a way to solve by myself and nobody most especially not my dad was going to to help me and it was then that I knew I wasn't a child anymore.
It's sad because I actually miss being a kid, I never had to worry about anything and if I needed anything I'd just tell my old man and let him worry about it. Now I have to deal with things myself and although I'm happy that I've become a man, sometimes I just wish I could be a kid again.
I think most people realize that they aren't kids again when they have to take up responsibility of some things or for themselves and if you ask me, that's only natural.
I hope this helps.
When I was a child, I talked like a child, thought like a child, went for something less valuable and when I became older I realized some sense of maturity to start talking as an adult, thinking as an adult and realized what really matters.
As I started to grow ,I begin to forfeit some of the attitude I was holding on as a child, I began to realize certain changes in me, from my physical changes to my emotional swift then to my reasoning. As I began to notice all these, I knew something was happening to me and that is called maturity.
We have more control over our life, activities etc in our adult lives.