what does "i think therefore i am" confused and have headache mean ?

I am a sentient being. Take 3 Tylenols and a nap.

THe opposite of "I dont think therefore i am not" No seriously, how could you think at all if you did not exist. This is taken as proof that you do exist. An axiom of Renee Descartes.

It is just a funny amending of French philosopher Rene Descartes famous axiom "I think therefore I am"

personally i think i was created and exist in Lisa Simpson's petri dish :-)

You can doubt the existence of everything but your own. The general idea behind this quote was that Rene Descartes was trying to rationally "prove" that because he was able to doubt and ponder about his own existence, he must therefore (at least) mentally exist.

In other words... what cannot doubt, does not exist.

Means, thinking too much would lead to ambiguities in the decision to be taken and it will increase the number of possibilities or alternatives leading to the pain in your head (that which alternative to choose)

I think therefore i am means the only thing you can know for certian actually exists is yourself