Ouch.
Yeah, in one of my chats-with-younger-self I’d have to answer the “Why don’t women appreciate what a nice guy I am?” question with “Because you’re a putz when it comes to women you’re attracted to.” I attribute my success with my wife (coming up on 16 years of marriage) with my initial confusion as to her marital/motherhood status (you see a desk photo of someone surrounded by six kids — why would you NOT assume they were hers, rather than nieces and nephews?), so we got to be friends before I realized she was available.
How can a guy avoid being a putz when attracted to someone? Dunno. I don’t even have advice for my younger self, and I know me better than most.
FWIW, my bright, personable lesbian friends turned into drooling morons when they got attracted to someone. So at least it’s not just a Y chromosome thing?