I don't fear death, but what I don't like are constant health problems when you get older. My grandma complained about her health problems constantly - it was so annoying.
There is also a strong influence of mindset here: there are people who are psychologically able to handle far more painful situation and still enjoy whatever satisfaction reachable to them, when other will lament all day along how sad they feel when they have best health and great social situation but can’t afford whatever luxury thing that might be above their current wallet.
To be clear, this is not to blame your grandparent. We all deal with situation with behavior that life forged into us. But if your opinion is that free will exists, then you should probably agree that there are ways to improve ourself.
Well, start take care of oneself, regular but not exaggerated physical exercices, good nutritional habits, sleeping enough each day and having balanced social interactions: these are all well known and documented.
