It was losing friends younger than me to standard old age illnesses; heart failure and dementia respectively that put the wind up me.
Up until they died (2022 & 2024) friends who had died, died of cancer, relating to genetic inheritance or smoking, or things not necessarily specific to old age.
However, I cheer myself up by thinking of DS's MiL, 89, this year, 7 years my senior, still living at home and with all her marbles. She has stopped driving but is fortunate to have both daughters nearby and has been incorporated into their wide and ecletic social circle, so still getting about and going places.
When we go north to visit the family in a few weeks time, we will stay with her for three nights. Every time we visit I query whether we should stay in a hotel, the answer is always 'no', but we do now take our bedding with us to save her having to change bedding. I look at her and it gives me hope.