Well... Consider the amount of time people spend on forums everyday, just to interact with other people about similar interests. Friendships can blossom, people often discover new things about themselves, and we watch ourselves grow as individuals. And as it becomes more and more routine, you realize how much it matters to you. There's another community I've been a part of for 10 years, and I've made absolutely amazing friends there, who have helped and supported me when I was discovering new things about myself and have been struggling with real life stuff, and I to them as well. They've all made a massive impact on my life, and to think, I would've never befriended any of them had I not simply registered an account there. Something that small, that I took 10 seconds out of my day to do 10 years ago snowballed into something incredibly huge for me. So, we make posts about our milestones when our post counts hit nice, big, round numbers, because they really represent how much time we've spent there and how important that time has been to us, whether we want to admit it or not. Of course, not everyone gets the same experience from the next person, but in the case of having 25k posts, this place must be important to FalKoopa regardless of if he'd posted about his milestone or not.