[senordevnyc]

It quite literally is the only thing we can know for sure exists

To be precise, it's the only thing I can know for sure exists. I can't know for sure if anyone else knows it.

[moi2388]

What is? Consciousness? Are you conscious when asleep? No? Then how do dreams work?

The only thing you can be sure of is that you experience some qualia; that you are conscious is an assumption.