It's very easy. Astronomers discover thousands of things every month, but only a few of these are really spectacular or significant enough to merit writing them up in a research paper and having them published. This is an exciting time because there is still so much 'out there' that no one has yet looked at carefully. You never know what will turn up. Astronomers have assembled hundreds of catalogs of objects in the universe, but only a small percentage of them have been looked at carefully. I am still making discoveries in a catalog of 300,000 infrared sources in the sky that was put together in 1984. In another 5 years, there will be a catalog listing over 100 million galaxies and several billion stars.
No astronomer will ever look at every one of them in detail. Instead we will comb through these catalogs and search for objects that meet certain characteristics we are interested in studying. Still, no matter how you do the study, you will end up with thousands of objects matching your characteristics. It will take years for you to look at each one, if that even turns out to be important to your study at all! Instead, you will probably only look at the few dozen odd balls and examine them carefully. Most of the objects we already know about in our catalogs, will remain anonymous and unstudied, unless some feature of them is deemed unusual by some further survey we may perform at a later time.