The speaker starts with a familiar idea: forever is a huge, almost tiresome stretch of time. It's the kind of word people use without really feeling its weight. Then comes the turn. Since meeting someone, the speaker finds that time has flipped. Forever no longer feels long, and even all of it wouldn't be enough.
What the speaker feels is a mix of love and a little urgency. Being with this person makes time seem precious and too short, as if every moment is slipping by too quickly. It's a tender kind of worry, the sort that comes from wanting something to last.
The mood is quiet, intimate, and sincere. The plain, conversational wording, without fancy images, makes it sound like a private confession rather than a performance. The lowercase, untitled feel adds to that sense of a thought spoken softly, just for the person it's about.