I agree with the quote "We thing, therefore we exist". I think that it is really all about what we perceive as existence. And sometimes it really is just about what we need to believe in. If we think that something is or exists, then what is there to tell us otherwise.
The act of thinking and self reflection does indeed serve as a confirmation of our existence. The nature of that existence, and it potential for multiple layers of reality, or a unity transcending perceptions of individuality, are not ruled out by this logic. We exist, but the exact nature of our existence remains a mystery.
Yes, I agree with the quote, "We think, therefore we exist," because they are correct that we are nothing without thinking. Life does not have meaning if you do not think for yourself once in a while. Life does not have meaning if you do not experience pain, joy and the emotions of life.
The problem ( I have) with Descartes Cogito, however, is that it is somewhat of a logical fallacy (circular reasoning?). We think therefore we exist. Even if I doubt it, I am thinking. Therefore I exist. But thinking alone doesn't necessarily provide solid proof that I exist. I can think but what if I'm living under the illusion of thought? I cannot think myself into existence ... And what's most real to me is certainly not my thoughts (reliability issues). Now Descartes would say that the sense are flawed because they're highly subjective ... But aren't our thoughts as well? How can subjective thought patterns (and thinking) be the ABSOLUTE PROOF THAT WE EXIST?
"We think, therefore we exist," is an interesting quote but I wouldn't say I totally agree with it. I do not believe our minds create all that we see. I think this world would exist regardless of rather we think and chances are, I would exist, even if I didn't think.