What will I leave behind when I'm gone? What will be my legacy?
I'm not sure what is a "normal" amount to think about such things, but I do think about them.
Perhaps losing my father at a young age and then attending his funeral initiated some premature awareness that people could die and that there might be some variability in how they are thought of and remembered. As I came to terms with the existence of my own mortality, I more than occasionally wondered what might be said of me at my funeral, and how I would be known from that point on.
Of course it's an incredible privilege to even think about legacy, and dwelling too long on it can bring out the worst impulses of ego and self-importance. To have had incredible opportunities and access to resources over the course of my life and then still try to control how the world works even after I die...well, that would be crazy.
So I try to use any "legacy thinking" as a way to keep me focused, especially on the important things I want to do in life and the kinds of relationships I want to have, instead of as a vehicle for self-inflation or unnatural self-preservation. I also use it to keep perspective:
On a geologic time scale, I won't really have any personal legacy. I will be one of many billions of people who lived in a time when humans inflicted substantial, mostly harmful changes across the planet, killing off many other forms of life while altering the climate, poisoning the water, bringing up oil and putting down trash and toxic chemicals, and just generally making a mess of things while we wait for the sun to implode and swallow the Earth.
Hopefully I also live in a time where a shift in human attitudes about the planet we occupy eventually leads to some reversal of those trends, and maybe our descendants will despise us slightly less than they could have otherwise. But as much as I want to believe that I personally can make a difference in reducing this harm, I don't currently hold out hope that my lifestyle choices will be worth much when measured across the millennia.