The brain may need to discard information to accommodate new learning due to limited memory capacity.

“The brain can only hold so much information. And if you are undergoing rapid learning to learn to acquire new knowledge, you also have to put memory or information in the trash like in a computer. You you only have so many gigabases of memory. Plus also for survival, you don't want to keep forgetting things. And so so the brain is designed I believe to undergo this critical period and solidify the circuits with what you learned as a child and you use that for the rest of your life.”