Neil Patrick Harris was 14 in Clara's Heart when he played the character 'David Hart'.
That was over 36 years ago in 1988.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
Today he is 50, and has starred in 79 movies in total, 78 of those since Clara's Heart was released.
In Clara's Heart, I think Neil Patrick Harris looks: