Death

I went through a bit of a rough patch about 7 years ago, mom passed in November, and then my uncle in January. They were the last two of their generation in our family.
I started freaking out because this meant that me and my brothers are the "old people" in the family now, and it's our turn to start dying off.
For about 6 month I was walking on eggshells thinking that any day now I'm just going to fall over dead of a heart attack or something. I eventually got past it, but it's still kind of in the back of my mind.