There are a lot of awful things that can happen to a person and I think being irrelevant makes the list. It doesn't sound THAT bad but, if you think about it, really think about it, you'd realize how miserable and useless it can make you feel.
We are social human beings and we cannot live without interacting with other people. We go insane if we don't and it's not an exaggeration. However, you can interact all you want but if what you have to say, what you feel or think doesn't have the tiniest impact on anyone, you start to feel more like a ghost than a person. If your opinions aren't valued, if you're actions don't strike an interest in anyone, if you're constantly being overlooked, you are going to think "what's the point?"
Well, there's always a point. Your actions, your voice, might not always influence or get people's attention but, in the long run, they will shape YOU. They will mark your journey so that when life gets confusing you can find your way back to your true self.
That saying 'Stay true to yourself' is a cliche for a reason.
With that in mind, go outside and have an awesome day!