No matter our age, most of us are guilty of saying, “I must be getting old,” when we can’t quite find the words to describe something or an important item on our to-do lists slips our minds. Indeed, our brains do change with age; research suggests that the brain shrinks about 5% per decade starting at age 40. But as we get into our 50s and 60s, what can we expect to happen to our brains? What little slip-ups can be attributed to normal brain aging, and what can signify something more serious?