Memorizing is not an excellent way to learn as it gives you a superficial understanding of a concept. You then store this information in your short-term memory as opposed to your long-term memory.
Instead, look to understand the why behind what you have learned. This calls for an understanding of life applications. What this does is help you understand what you are learning better and demonstrate the real-life problems that you are learning can solve.
Another important aspect of studying stats is identifying recurring themes. Once you do this, you are operating from a much deeper understanding.