What is the point of twitter?

Can someone explain the point of twitter for me? I made one about 2 months ago and I just don't see the point of it, it's cool seeing celebrities tweets and stuff but who cares what I have to say? If anything I fell like I'm talking to myself. I'm 17 and all the people I follow are 17 and they have like 10000 and up tweets. It all just seems pointless.