Thesis defense months after thesis submission I submitted my PhD thesis a few months back, and it's still not clear when I will have my final defense. 

Since then, I have moved on to industry, and I'm very much worried that the state of my knowledge will not be at its peak when my defense finally comes. I feel that at the time of my thesis submission I knew "everything" about my thesis and could answer any question about it, but now, even if I will read it a few times, it will not be the same.

I do have papers published, so one can say I have some "proof" of the thesis merits, but I probably won't be able to defend them to the fullest, so to speak.

I'm wondering, is that something the committee realizes, or do they expect of me to be in "top shape" when coming to my defense, in that every little question I cannot answer will reflect badly on my part? 

Thanks.
In my culture the thesis defense is just a formality. Basically when the supervisor allows the thesis submission he is sure that you had produced more than enough to receive the title (publishing papers, attending to conferences, etc). 

Thus, even if you are not at the best shape for the oral proof, probably it will be enough to be approved. However, slipping the answers of one or two questions could be the difference between the top qualification or the second best.

In my university we have three qualifications for approved theses: "Cum laude", "Magna cum laude" and "Summa cum laude". And it is attributed the status of "Approved by unanimity" or "Approved by the majority".