You people are so boring. omg.
I usually mention that it's my birthday a couple times just to remind people who may forget or just people you wouldn't know in the first place. It doesn't bother me if they forget, though a good amount of people usually remember. I haven't had a party in a while , since I was at least 8 I believe. My dad could never afford to have them is why, but then it got to the point where I didn't care if I had a party or not. The most that happens on my birthday now is that my dad takes me and my brothers out to eat for dinner at a causal/nicer restaurant (nicer than fast food) . Usually a diner or bar and grill place like Applebees. Though going to diner for 3 birthdays a year can get expensive so there's been a couple times where we didn't got for 1 or 2 or even all three of us. The least that happens is that my dad makes or buys a cake and we all have it that night for dessert. I'm lucky that my 21st birthday was so close to my little bro's high school graduation this year and my aunt did a combined graduation/birthday celebration at a nice bar/grill after his graduation ceremony or we would of just gone to a cheap diner like Steak n Shake. (Not that I don't like Steak n Shake, I love that place.)
On PC, I celebrated/announced my 1 year anniversary by making a thread for it. On my 21st birthday, Hikari made a birthday thread for me here on PC and Palamon (Yuki's Sword) made me one on Evergrande City, another Pokemon fan forum. For future anniversaries and birthdays I might make myself a thread or if someone else volunteers to make one for me , then I'll happy accept them to do that. If no one does and forget to make one myself, it won't matter.
Other things it depends on the occasion. Anniversary of a relationship hasn't happened yet cause I have yet to even be in a relationship. But when it does happen, I probably will celebrate only for major milestones: maybe 6 months, definitely 1 year , 2 years, 5 years, 10 years, etc. By ten years I should be married to that person if it's lasted that long, then I'll celebrate wedding anniversaries of course. Probably with a special gift or a taking them to dinner. Anything else I announce it or celebrate only if it seem like something people should know or is important to me like getting a job or graduating or getting my driver's license. Stuff like that.