Yes, the last stanza of the poem ‘I Believe’ is very much different from the previous ones. But this stanza can be looked at in two different ways.

Firstly, In the first five stanzas of the poem, the poet talks about what she believes regarding her ability. But in the final stanza she reminds us that we should not forget the ground reality. We should not get carried away by our dreams but work hard in the real world to achieve any kind of success.

Secondly, the poet may suggest her own bindings and limitations in this life that are preventing her from doing what she believes she can do. Some critics suggest that the poet, being a woman and coming from an underprivileged community in India, does not have such freedom to pursue what she likes and believes. Rather, she has to abide by the rules made by the society and have to give up on her own dreams.

So, going by the second interpretation, the poetess, in the first five stanzas, has talked about what she believes but in the final stanza expresses her regret that she cannot do all these because of the limitations put by the society on her. She only has to “complete the role assigned” to her here on earth.