Even to me at first it seemed like bullshit, but I have a feeling this could be a really interesting story.
I believe that the author wants to convey this message: insecurities and paranoia possess the person and deform his sight, showing only the bad things in life. Here the protagonist drowned in his low self-esteem.
But maybe I'm reading too much into a simple manga
Of course, the premise "I want to be her first time", if repeated to exasperation, makes everything more superficial but it could become a simple motto without it being the center of the story.