I am assuming from your description that you do not actually know this girl in real life? Do you have a significant other in your life right now at all? Depending on the answers to these questions she may represent someone specific or just a generic representation of a special girl or of a relationship. Let's assume for a moment that she is thre as a personified representation of "a relationship" in general, then the message could be that if you want to have or keep a relationship you have to fight for it, you have to put in an effort into making a relationship happen and making it last. And that is true I have found of relationships in my life: they are not just something we can have and take for granted, we have to actively work on keeping a relationship alive and on developing it further or else it will not work out. There are distractions throughout life (such as your grandfather with the guitar) but it is important to not let the distractions distract one from the goal of having and nurturing relationships - and btw the relationship could be just a friendship, it applies to any relationship between two human beings. She forgets something in the house, does this mean that something is forgotten in the relationship, something important is missing, and let's not forget it. But you do not join her to go back into the house, and this could mean that you feel that you are not actively enough engaged in ensuring that what was forgotten is regained in relationship, and thus the message to you that you have to fight for it, you have to put in an effort, you have to be actively engaged, or else the other will perceive you as not caring enough, and that will put a relationship at risk. Does that sound right to you? If not, please disregard, and look for another interpretation.