I might be misremembering, but talking with a friend years ago he was talking about a "New Scientist" article that described how the brain is flushed/cleaned of

I might be misremembering, but talking with a friend years ago he was talking about a "New Scientist" article that described how the brain is flushed/cleaned of most memories at age 4 and again at age 7. Or something like that. I was also surprised with my kids at 4-5 remembering when they were 3 or so, but now those memories seem to be completely, or near completely gone (at age 10). Perhaps they are just remembering the remembrance.