Bro, the humans have limits in their memory. You can experiment with this by yourself. Read some articles; now try to recollect that information the day after. Can you recollect it? No, most of us can't. So we need to reread those articles. By this exercise, your brain cells that are responsible for that particular memory will be activated. If you practice, what you're learning will continuously be activated. The brain keeps those highly activated memories as important and will keep them even longer. so it will be a permanent memory. So keep practicing - consistency is the key. Remember, you need good sleep too. Because it was the night time that the brain kept sorting those memories and keep highly active memories as important. Good luck.