I'll keep it brief because I know that this kind of stuff is very triggering for some people but when I was in elementary school, my dad was an alcoholic. One year on my birthday, we decided to go out of town so we can eat at a restaurant that we didn't have and buy some games from GameStop. Long story short, right before we reached our destination, my dad for a reason that I don't remember (assuming there was one), decided to start physically abusing both my mom and my sister. So we ended up just going right back home and we just ordered pizza.
Was invited out on a Friday to celebrate my bosses birthday early since she would be out of town on her actual birthday a week later. That Friday was my actual birthday. My boss had made a point to do something for every one of her employees birthdays, so I assumed this was a ploy to get me out for my birthday. Nope.
I learned that the lump I'd had biopsied on my neck was a pair of thyroid tumors that were suspicious for cancer, and that the whole organ would need to be removed. After pathology, it turned out not to be malignant, which is lucky, but that was a pretty unpleasant few months and now I have to take thyroid replacement hormones for the rest of my life. The doc still hasn't got my dose quite right, so I just kind of low-key feel like shit all the time. It takes a couple months before we know if a new dosage is working better or worse. Hopefully they'll have it figured out by my next birthday...
My birthday is September 10. September 11 2001 happened. While I'm not directly affected, it messed me up mentally because I thought I had something to do with it. It didn't help that the year after, I saw Space Shuttle Columbia on the launch pad in what would be its final mission.