It looks like you might be asking about Taylor Swift’s song “the 1” from her 2020 album folklore. Here are a few details about the song:
Theme: It is an introspective song about looking back on a past relationship with a sense of nostalgic acceptance, rather than deep heartbreak.
Lyrics: The song features conversational, sometimes humorous lyrics that explore the idea of “what could have been,” with lines like, “It would’ve been fun, if you would’ve been the one”.
Meaning: It deals with appreciating the present while acknowledging that a past “what if” relationship didn’t work out, as described on PopSongProfessor.
You can listen to the official lyric video for “the 1” here: Taylor Swift – the 1 (Official Lyric Video) Taylor Swift YouTube · Jul 23, 2020
Is there something specific you wanted to know about the song or its lyrics?
If you were referring to something else (like the number 1 in mathematics), If you’d like, I can: Analyze specific lyrics from the song. Compare it to other songs on folklore. List similar songs about nostalgia.