Ever since I was young I've had the internal narrative that I don't matter THAT much. People have tried to change this but no matter which way I slice it, I have always logically had to come to the same conclusion. I don't say this to be woeful or sad, I have my reasons. Emotions and what society wants you to believe about yourself aside, the world is so self-involved that the average person living their normal life does little to affect the grand scheme of things. Take, for example, me.
If I were to right now at this moment to disappear off of the face of the Earth radius of my effects that my nonexistence would notably impact is tiny.
There are a few people I know my death would wreak havoc upon. My parents and siblings would suffer the weight of my grief the heaviest because as a family member it's impossible for anyone to take my spot. My parents are not having more kids after me, so as a daughter and sister, I literally can't be replaced. However, this grief would become less over time until I'm just a passing thought. It might take a few years but their lives would go on. The same applies to my friends and the close surrounding community. People would grieve the loss collectively for probably a week. Then they go on as well. If I were to cease to exist people would adapt and learn to live without me. I'd be replaced at work as well. The people I've lost touch with over the years would feel little to no effect to my leaving.
Maybe a few would unfollow me on social media after sensing I've been quite inactive.
Depressing but true points out of the way, the nature of people's short attention spans can and should also be viewed in a more positive lens. You can definitely impact people's lives positively and negatively. However, over time, things blow over and have less of an impact and fade into memory. The hope is you leave fond ones. No one is paying as much attention to you as you are to yourself. So don't be afraid to be yourself. If you do something embarrassing, people will forget. If you start something and don't succeed at it, people will forget.
Follow your dreams because you have to live for you, and it's no skin off of anyone else's back.