Don’t be.
You are going to die. There is no point worry about it.
The more you worry, about something that is inevitable, the less enjoyment you will have in the here and now.
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However, I realize that this pithy advice isn’t very helpful to people who worry a lot.
It’s not like you have a huge amount of control over the whole worrying thing.
Which is why I think that coming to terms and accepting your death is so helpful.
A lot of worry is about trying to control things you can’t control.
Trying to figure out ways to avoid the thing you are afraid of.
When you accept your mortality, you no longer have to worry about it.
It’s inevitable. No getting out of it.
Now stop worry and get on with making the most of the time you have left.