In order to thoroughly learn something, as opposed to memorizing and regurgitating the information (which is usually followed by promptly forgetting the information), one needs to have critical thinking skills. This means that you can articulate what it is you are studying, you are open to all possibilities of what you may discover, and that you can assess, review, understand, and draw your own conclusions based on what you have learned.
As you are gathering information about the subject, do not limit your resources to just textbooks. Think about a variety of ways you can access information. When you read, study, and review the information you gather, ask questions. Do you accept what you are reading as the truth just because it is in black and white in front of you? Who wrote the piece? Could they have any biases that would lead them to their conclusion on the topic? Could they have omitted important information relevant to the topic to fulfill an agenda? All of these questions will help you to critically analyze the information.
There are six steps to the critical thinking process. The first step involves demonstrating you have learned basic knowledge about the subject by being able to list and identify main components of the topic. Step two is understanding the topic. Can you summarize it in your own words? Can you explain it to someone who has no prior knowledge about the topic? The third step is applying the knowledge you demonstrated in steps one and two. Can you take that information and apply it to a different set of circumstances? Step four takes it to another level because you need to be able to analyze the information. One way to do this is to compare and contrast it. The fifth step involves not only breaking down the information, but being able to synthesize it with what you already know. Can you combine it with prior knowledge to create something new? Finally, the sixth and final step asks you to evaluate, explain, and assess the information to come up with your own conclusions.
Critical thinking is a skill that will allow you to take studying to a whole new level. Instead of accepting information at face value, critical thinking allows you to discover, question, formulate new ideas, and reach your own conclusions.