I do most emphatically and unequivocally declare unto thee that indeed, mine age doth far surpass the venerable milestone of eighteen years, that sacred threshold which doth mark the passage from youth unto the full flowering of adulthood in the eyes of law and custom.
If I'm being honest, I was born in the year of our Lord 2005 to the most amazingly loving, caring, and down-to-earth parents a child could ever ask for. At the tender age of 18, I lived life to its fullest, moved out from my parents' house, and then a year later I turned 19 for the first and only time ever. That was a turning point in my life, after which I was and forever would be over the age of 18. So yes, emphatically yes, I am indeed over the age of 18.