The poet in 'Go and Catch a Falling Star' decides at the end of the poem :

In the final stanza of John Donne's song 'Go and Catch a Falling Star', the speaker concludes that even if a woman both fair and faithful were reported to live next door, she would turn false before he could arrive to meet her. He therefore decides 'not to search for a woman who is both fair and faithful, because it is impossible to find one.'