All there is

“This is it”, or “this is all there is and there aint no more”, when referring to life, may sound like very negative statements.
“You are it”, or “you are all there is and there is nobody else like you”, on the other hand sound like very positive statements.

When referring to life what does it mean to say “this is all there is”, and is it really negative to say it?

The statement probably sounds like an “end”. When speaking of life “end” sounds negative, but when referring to a person as the “end” it may be thought of as a very positive thing to say or even flattering.

An end usually means something is over. Some “thing” being key. When we say some “thing” is over, what we mean is that the thing is no longer the way it was. To us, it has ended. Really it has changed. Ended, changed; what’s the difference?
Obviously on the level that we would like it to be there is no difference. Of course we would like things not to change, or at least not to end.
This doesn’t seem to be the case however. Is this a negative thing to say?