Cogito 

I think therefore I am. 

So Descartes. 

But Sârtre 

said 

'This thought's an 'is' 

as pre-reflection since 

Existence is an is 

prior all Essence is.' 

Therefore my thought that thought implies i am is a thing unthought before it's thought Such that 

"I think the thought unthought but that's not known as unreflective so until I've realized that in thought" 

so 

[I think (i think therefore i am) therefore I am.] 

But then why not 

[I think (i think { i think therefore i am } therefore i am) therefore I am.] 

i.e. my thought of just that thought of thought within and then why stop 

at that, why not go on since here i am betwixt facing mirrors seeing myself in sight of self like leaning flip of row dealer's cards or the dominoes of a gazillion shards 

One each of me per cosmic dream, a repeating endless panoply of me i am, i am me in universe of infinities!