Suppose the following
X is not necessarily not Y.
If X is Y then X necessarily cannot be Z.
Does that mean X cannot be Z?
I probably screwed up stating that...
The first line is meant to be a solipsistic statement - I may be all there is.
The second line is meant to state that if I am all there is then I cannot imagine being annihilated.
In the third line I conclude that I cannot imagine my annihilation.
I'm not concluding that we must "live" forever in oblivion but it's kinda the idea.