Robert Frost - Carpe Diem

Age saw two quiet children
Go loving by at twilight,
He knew not whether homeward,
Or outward from the village,
Or (chimes were ringing) churchward,
He waited, (they were strangers)
Till they were out of hearing
To bid them both be happy.
'Be happy, happy, happy,
And seize the day of pleasure.'
The age-long theme is Age's.
'Twas Age imposed on poems
Their gather-roses burden
To warn against the danger
That overtaken lovers
From being overflooded
With happiness should have it.
And yet not know they have it.
But bid life seize the present?
It lives less in the present
Than in the future always,
And less in both together
Than in the past. The present
Is too much for the senses,
Too crowding, too confusing-
Too present to imagine.

Robert Frost

http://www.poemhunter.com/poem/carpe-diem-36/