Okay kiddo, so imagine your brain is like a big piggy bank, but instead of coins and dollars, it saves memories!
Every time you learn something new, your brain puts it in a special spot in the piggy bank, called a "memory bank".
So if you go to school and learn how to read a new word, your brain puts that new knowledge in the memory bank.
Then later, when you need to remember how to read that word again, your brain goes back to the memory bank and pulls out that knowledge so you can use it.
Just like how you go to your piggy bank to get your coins when you want to buy something cool!