What makes you think you’re still alive?
Because we can change. The non-living can’t change.
I think, therefore I am.
Descartes walks into a bar. The bartender asks him, “Can I get you something to drink?” Descartes replies, “I think not,” and vanishes. 
By the way, great username/post combo!
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I don’t see a factual question here.
Moving thread from General Questions to In My Humble Opinion.
A ghost realized he’s dead, and changes his behavior accordingly. Is he back alive now?
You THINK, but do you UNDERSTAND?
I am not dead, I hurt too much
Sadly, the reverse isn’t true, as any trip down the freeway will tell you.
I’m warmer then room temperature.
I’ve got a pulse.
Eating and digestion seems to be working properly.
I had an itch.
And a shower washes away the bad smells.
First of all, pain, or hurt is an interpretation to a stimulus, its not a raw feeling by itself. Secondly, pain can also be an illusion. People with limbs amputated sometimes feel pain on a bodypart that is no longer there.
So how do you know you’re not just a ghost?
Those are all observations you made using your physical senses. How do you know your senses are even real?
I came here to say this.
Were I dead, I would lack the faculty to contemplate the question of my status.
Rotting corpses can also stink.
Say you were a ghost, wouldn’t you still be able to think?
Except corpses can’t smell themselves. If they could, they’d use Old Spice.
Because I’m still paying taxes.
I do/am able to do the following:
-Reproduction
-Digestion
-Homeostasis
-Interact with other organisms
-Stimulus response
I’m sure there are other signs of life too, but that is basically what was explained as the definition of life in 8th grade science class.
If I was dead, I’d be sleeping better.
If a ghost can do that, by any definition that matters to me, he’s alive. Is your question actually, “How do you know you haven’t passed into the after-life?” If it is, my answer is, I can’t be sure.
As said, if I were dead I wouldn’t be able to think of the question. And there’s no such thing as ghosts.
Cogito ergo sums it up nicely. I sure hope once I kick the bucket I will no longer spend my saturday nights answering questions like this.
Of course the whole thing depends on your definition of “dead”. My definition of being dead includes the inability to know things. So knowing you’re dead is impossible, leaving only the option of knowing you’re alive. Or rather, I should say “I” because for all I know, you are, in fact, not alive. (Which includes trollbots, which can’t be dead because they were never alive.)