Question

man may come and man may go but i go at forever

Answer 1

First of all there's a little error in what you've written. I've already answered this before.

Men may come and men may go but I go on forever

It is an excerpt of the poem The Brooke by Alfred Lord Tennyson.

It means men take birth and die but I(the river) keep flowing forever.

Answer 2

here I reffer to the Brook I. e. river in this the poet describe that man come take birth and die but the Brook flows on forever it never stops if it had an obstacle in its path but keeps on moving towards it goal the poet want to tell us that we should take inspiration from the river and should never stop by seeing our obstacles but she tried to reach our goal until we can.