Of course not... You can also wirehead yourself to avoid thinking of the impending doom!

I hope you didn't saw my comment as a real proposal for regulating billions-years-in-the-future civilization :)
It was more on the spirit of a Lovecraftian side note...

Although I think, more seriously, that a civ heavily invested in preventing death would be reasonably crippled if it suddenly find another, inevitable source of death. E.g. once anti-aging is widespread, a deadly virus that targets those who have been treated.