To me going back and analyzing my sessions is the most important part of my study time. In my opinion, if your goal is to improve you must be willing to look at your mistakes and find a way to keep from repeating them over and over. That is how low stakes players get stuck, if you hear someone say they are looking for "leaks" by reviewing hands. They mean that "we" develop bad habits over time, and if they are not corrected, they become permanent. Hand review lets you identify situations and board textures where you constantly make the wrong play. Now, the problem is identified, next you need a way to keep this problem from happening, this is where a better player looking at your hands will be able to help. Many times they have experienced the same issue and can give you ideas on what helped them to overcome