My father is 98. His health has declined gradually but visibly over the last 10 years. He's taking a mouthful of pills each day to keep himself alive. However, he's able to get up, walk, use the bathroom, feed himself etc. He can remember things that happened 5 minutes ago, last week and in his childhood. He keeps up to date with all the family affairs, and watches the news. Also my mother (his wife) is still alive and healthy, and they don't hate each other.

That's more than most people can expect if they even make it to their late 80s.

Frankly I'm astonished at people like Warren Buffet and David Attenborough (a hero of mine).