I relate to this profoundly. I'm 25, but I feel as if my maturation stunted at 17, likely even earlier. I was forced to "grow up" only due to number of extreme circumstances imposed upon me (arrested at the age of 12, involuntarily committed to a number of acute psychiatric hospitals & later a residential treatment facility from the ages of 15-18, kicked out of the house & forced to live on my own at the age of 21).
But despite periods of repeated hardship and adversity, I never truly grew up. Those experiences thrust upon me were never developmentally fruitful in any meaningful sense. Most people would harden from such personal austerity. Some would learn, some would grow. Not me. I only regressed, somehow became even more alien, more erratic, more ill-tempered, more detached from the world around me.
Now I grieve over a stolen adolescence and childhood. Forgoing the more desirable commonplace social milestones that so many share resulted in increased pathological neuroticism, social isolation, and general alienation. I am left as an empty chasm full of longing and desire for a time less troublesome, less lonely than now. I'm a child occupying an aged vessel by no will of his own, because the responsibilities of adult life have proven to be far too demanding and burdensome. Being an adult requires syncing up & engaging with your external reality. And confronting that reality is far more painful and taxing than retreating inside the rich internal cosmos constructed by the childlike imaginative mind.