Writers block

Don't you hate it when you want to write something amazing? But you can't. You try and try to draft a storyline but nothing comes into your mind. So instead you end up writing something rubbish, and feeling no inspiration to the story what so ever. This happens to me alot, and I never finish adding more to my work, so I just end it then and there. Many people ask to read what I've written and I just tell them "It's not finished." They always tell me to add more to it, but I simply refuse. If I can't think of anything, then I will not continue it. It's hard to keep an open mind when it comes to writing, especially if you want to write something different and unique, a book no one else has ever thought of. Thats the challenge though, people have thought of everything.