The quote hints at the dynamic nature of relationships. "Someday you are gonna send me a message out of the blue" anticipates a surprise message from someone.
"And someday I am going to have the strength to ignore it" suggests the speaker's eventual ability to distance themselves emotionally.
In essence, the quote reflects personal growth and boundaries. It conveys the idea of progress, showing that the speaker will reach a point where they can protect their emotional well-being by not engaging with certain messages. It's a reminder of the power of self-care and resilience in navigating past relationships, highlighting the potential to heal and move forward.