The song implies that the singer and his destined lover have probably connected in the past, but somehow failed to recognise or act on their connection due to various circumstances. As the song progresses, it expresses the singer's longing and hopefulness that they might have a chance to rectify past choices and find each other again in life.
The refrain "Chances are we've had a past, Chances are we'll meet again" underscores the notion of the cyclical nature of love and potential for reunion, even after a lengthy separation or missed opportunities.
In essence, the song conveys the idea that fate often operates in mysterious ways and sometimes brings people back together when the timing is right, providing them with another opportunity to embrace and explore the romantic connection that they initially failed to pursue.