For such a deceptively simple song, Bono's lyrics, as usual, speak to deeper truths. Bandmate Adam Clayton described Bono's writing style:
I always think what's amazing about Bono's words is you know that they're so personal to him and yet you know that they connect with a lot of people. They reflect the band's feelings as well as his, and that seems to connect you with the whole audience out there. He has a very hard gig as well because most of the time, ninety-percent of the time, Bono is trying to work lyrics into a piece of music that already has a strong identity and a strong feeling. So it's not even like he can sit down and write some words that he wants to write today and we write music to it, he has loads of that. Coming into this album he had big bunches of words and prose and ideas and notions, but most of that never worked in the context of the music we were coming up with. So he was in a position where he kinda had to go with the music, and that's hard, that's really hard.
In the case of "One," Bono's words conjure up concrete images while speaking directly to our emotions. At first, we can picture a couple, perhaps lying in bed, wide awake and unhappy, or even fighting and yelling at each other. It is night, and they are exhausted from arguing. They are in the throes of one of life's greatest catch-22's: Just because you're in love with someone doesn't mean that you two are right for each other in the end. It is heartbreaking, it is poignant, and we've all been there.
Or, if we lean toward an alternate interpretation of the lyrics—that this is the story of a gay son coming out to his disapproving father—the lyrics fit just as well. He and his father are "one blood" but they are "not the same," yet they must learn to "carry each other" because they are connected and need each other to survive.
As Clayton said, the single most important quality of Bono's lyrics is that they can seem both deeply personal and widely universal at the same time.