There are two ways to develop your brain: learning to think for yourself or accumulating other people's knowledge. Both directions, of course, are important, but it is the second that is usually called “broad-minded” and “highly educated”.
Instructions
Step 1
Develop your memory. There are many tutorials out there that will give you tons of options on how to do this. The simplest ways that we are taught from childhood is to learn poetry and prepare for tests. Of course, the education system is imperfect, and there is no desire to memorize something "out of hand". However, pay attention to the fact that just one desire to learn can increase the student's results several times. The point is that there should be a desire to work on oneself.
Step 2
Read classic or internationally recognized literature. During reading, a huge number of processes take place in the head that develop intelligence just because they are happening. At the first stage, the brain tries to recognize obscure symbols and concatenate words from them (at the same time, it determines only 50% of the word, and thinks out the rest itself). Further, a similar process occurs during the composition of words in a sentence; at the same time you draw a picture in your imagination in parallel and analyze, think over what you read. And if you read poetry, then a dozen more nuances associated with rhythm are added to this.
Step 3
Watch movies, study painting, play computer games. In other words, study everything that may have even the slightest relation to art. If you have any doubts about the last point, then here's another great tip for developing your mind: stop thinking in stereotypes. Introduce yourself to games like Braid and Bioshock. In fact, there are many projects in the gaming industry that are examples of impeccable taste and can deliver a lot of aesthetic pleasure. As in the "silly Japanese cartoons" - anime.
Step 4
Train yourself to write essays on what you read and what you see. At the time of writing, you will not only give a load to the brain, but also begin to ponder the work more carefully, find subtexts and thoughts that the author was trying to convey. Moreover, when you fully penetrate and understand the meaning of the book, you are unlikely to forget it in the next couple of years and can always show off your erudition in front of your friends.