I don't believe in an afterlife but I do believe that you do live on in some form of human memory, whether it's a random Twitter post or through the interactions people remember having with you. And it's not necessarily that you had to actually say or do something — not doing something can be remembered too, like if you're the quiet person at work, maybe someone just remembers that you existed as that person that wouldn't talk to anyone and no one else at work knew what you were all about. Or if you posted on Twitter, and no one replied, shared, or anything, but someone remembers you, looks you up, finds your post after you're gone, and you were a real asshole in that Twitter post and they're like "oh right, that person spent their life being fucking miserable to everyone." ;P
In any case, part of you does live on in the way you communicate, no matter how small or insignificant, it can resonate up through ongoing human existence nowadays. We're at a point where our communication and technology can seem more permanent and impactful than ever, and it creates a lasting memory of the person you were when you were a live perhaps more poignantly than ever, assuming it is preserved somehow. And I don't just mean digital social media living forever in the internet — that's just one part of it — but same as ever, sometimes people remember you even if you weren't the most popular or significant person in your social circles.
When you die, your personal participation ends, but your personality is likely out there somewhere still, in someone's memory or recorded in social media or something, living on through someone else's ongoing life.
