On being alive

According to Biology,
There are some requirement for life,
To grow, to move, to adapt,
To respond, to reproduce,
And to regain balance after a while.
 
That being the case,
I'm sad to say,
That there are people you could state,
Are not alive.
 
They are unhappily stuck,
Right where they've been,
But do not move, or find balance,
or adapt within.
 
They are impervious to stimuli,
And would find it hard,
To grow or bring new life,
since they close themselves to everyone.
 
Yet maybe I just have it wrong,
And confuse living with having life,
Since it is obvious we are all alive.
 
But I fear some would someday paraphrase,
Thoreau or Dead Poets Society,
And say: "I have life, so I will surely die,
But I am not so sure that I have lived."
So, I try each day for that terrible phrase
not to be mine.