The central idea of Nissim Ezekiel's poem "Enterprise" is best summed up by a well-known phrase of Robert Louis Stevenson's: "to travel hopefully is a better thing than to arrive." This phrase, like the poem, makes a dual point—that the journey is often exciting, while the destination proves to be disappointing.
The journey Ezekial describes begins in optimism, with the "Exalting minds" of the pilgrims making all their "burdens light." This positive attitude is able to carry them a long way through hardships and misfortunes. Eventually, however, some of the travelers begin to break away, and those who remain become "A straggling crowd of little hope." They feel that they have lost their way and, by the time they reach their destination, have forgotten why they wanted to reach it in the first place.
This is an allegory for the journey of life, in which attaining what you thought you wanted is often deeply disappointing. The hope and positive purpose the travelers had at the beginning of the journey was their greatest possession. Once they have lost this, it does not much matter where they end up. The ones who reach their destination seem to have lost their way just as thoroughly as their former traveling companions who have failed to do so. This is because the "way" in question was an attitude of mind rather than a geographical location.