When it comes to these people living that long and through god knows how many wars revolutions etc its a triumph or its a lie either way even if shes just 90 hell she still survived. now as far as your brain deminishes over time no. as you age you get complacent and have no desire to learn esp when your in the same job for 30 years why should you. but those people who keep learning are those with great minds yet may be old. its all realitive truthfully. no one even knows why we need sleep i mean come on theoretically we should be able to stay awake constantly but yet we can't our brains can't handle it. our bodies each do something strange yet not even science completely understands.