Songwriters look for things to write songs about constantly...
John buys an poster with interesting words and writes 'Mr Kite'
Paul remembers going on Sunday drives with Linda to see if they can get lost, and writes a song about it
but for the listener it can be about whatever you want.
Yes, I think so. I write songs too and something inspires me to start a lyric, but then the words come alone and complete it, perhaps with a different sense than the original intention. So I always think about the original inspiration when I think about my song, but I still know that it can be read in a different way.
One curious song for me is "Triad", written by David Crosby when he was with the Byrds. The song is really about polygamy, starting with the line "You want to know how it will be, me and her or you and me". But when I hear the version by Jefferson Airplane, sung by Grace Slick, she sings "You want to know how it will be, me and him
or you and me"; it has a different meaning to me. I think about the "triad" formed by Woman-Man-Jesus in every Christian marriage.