Interesting question. Obviously, you can't be asking for age "in years," since the measure of a man's life isn't shown in minutes, times, and hours. Nor are you asking for the vocation of a reader of Shakespeare (like "high school student" or "undergrad), for though one man in his time plays many parts, Jaques' trite observation about the human comedy wasn't a full picture of human life either.
I'd side with the perspective or Prospero or Duke Ferdinand:
Thou seest we are not all alone unhappy:
This wide and universal theatre
Presents more woeful pageants than the scene
Wherein we play in.
And
Our revels now are ended. These our actors,
As I foretold you, were all spirits and
Are melted into air, into thin air:
And, like the baseless fabric of this vision,
The cloud-capp'd towers, the gorgeous palaces,
The solemn temples, the great globe itself,
Yea, all which it inherit, shall dissolve
And, like this insubstantial pageant faded,
Leave not a rack behind. We are such stuff
As dreams are made on, and our little life
Is rounded with a sleep.
In other words, no one should read Shakespeare until has dawned on them the awareness that one is finite--after the death of a loved one, wishes denied and depression endured, true love lost or thwarted. Any time in a man's life when he is shocked or nudged out of his shallow narcissism (the chief evil of our age) and has eyes for a wider vista than his own, little life. When Anxiety and loneliness threaten to creep in, that's when the genius of Shakespeare and comfort, thrill, amaze, and calm.
...too much? 'Cuz I'm being serious here.