Eighteen, the dawn of adulthood.
A prelude to a greater adventure. What sets now apart from then is this exhilaration, this hope that a new life waits ahead. A life of hope.
Eighteen isn't the age one should stop striving to grow at. Being eighteen doesn't declare that you're grown-up enough, nor does it mean one can adopt less of one's sense of coherence and rationality. The fact that this age marks independence -- to an extent -- is all the more the reason greater efforts must be made to continue maturing.
In reality, you are alone, hence the necessity to grow to be more mature. Ultimately, you are alone, and the only thing of yourself trustworthy and dependable is your rationality. There would be no one to consult, and only God can guide you through. That suffices.
Eighteen's the age you wake up from your pipe dream.