Maybe you're hitting too close to home with him. I went to rehab when I was graduating high school, the legal drinking age was 18 then. Right after I got out, my one step brother gave me a bottle of wine for my 18th birthday. He'd tense all up if I mentioned rehab or AA or NA for that matter. Later on, many years later, he has done his share of recovery and prison for that matter. It used to amaze me how taboo it was for me to talk about it but now we're both in our 40's it makes sense.