What's the point of observer pattern?

I'm currently learning Java and it's quite interesting but something really bugs me. I understand how to use the observer pattern but I can't find any real use for it. I've obviously saw some examples but i've found that it would make the code more complicated and that there were many simpler way to do those stuff.

So if someone has a simple explanation/example where the Observer pattern would really have an utility, I would appreciate.

Thanks