At 70 things seem to become  asymptotically worse like heart lung arthritis problems etc

People close to your age are dying like flies or severely compromised and you seem to be at first continually surprised this is happening and then realizing it's going to happen to you whereas in the 60s it's a gradual decline (see 56-65)

When you become the true orphan meaning no brothers sisters or parents (you are the only one left in your immediate family) it's a really strange feeling even if you didn't get along with one or more of them you are the so le owner of memories and even those may be someone distorted.

It's even scarier when you have no children and some of your close friends have passed on already.

Having a couple or three friends now that are in the same state as me and we're taking care of other people or have taken care of them who will be taking care of us the caretakers?

Irrelevance increases maybe not day by day but you notice it when people briefly talk to you because they're also afraid of the biggest taboo which is death and are starting to distance themselves from you.