Read ths excerpt from “break, break, break” by alfred loryd tennyson. what is the theme of the poem?

break, break, break,
on thy cold gray stones, o sea!
and i would that my tongue could utter
the thoughts that arise in me.

o well for the fisherman's boy,
that he shouts with his sister at play!
o well for the sailor lad,
that he sings in his boat on the bay!

and the stately ships go on
to their haven under the hill:
but o for the touch of a vanish'd hand,
and the sound of a voice that is still!

break, break, break,
at the foot of thy crags, o sea!
but the tender grace of a day that is dead
will never come back to me.

life seems like the endless ocean.
one man's grief cannot stop progress.
a moment lost in time does not return.
people do not understand the true meaning of life.