There are two parts in this: useful information how much your brain can handle Useful information is very difficult to describe as there are many questions. How do you decide what is useful? Do you see the usefulness or are you maybe missing it? As you don't see it you never know if there is useful information or not. Maybe you should study it more intense? Answering all these questions is very time consuming. Your brain can handle a lot of information but it should be trained to reach the best performance. This needs a lot of training to analyze quickly and get the correct outcome. Information can be useless because of the brain not being able to handle it, so you should not delete the information, but rather train your brain. Our brain is by default not functioning optimal for that. One should find the optimal combination of information and handling capacity of your brain. Needs a lot of testing to find out what works best.