I'm not sure if this is sophistic or not, but if assurance isn't assured, how can it really be assurance?
I guess, answering my own question, some assurance or a sometime assurance would be better than none in the Protestant view?
I was trying to be both funny and serious. OOPS, again. :) What I meant is that it is not true that all believers say that they are assured. You might be an example. Perhaps in your mind you do not have assurance, so for you, the assurance which I think is true is not "assured". This in no way affects your salvation.
When I first became a believer, I probably would have said that I was 90% sure that I was saved. Then, after reading the Bible for a while, I said that I was 99% sure. Then, after a few years I was 100% sure. The assurance was actually there all along, it just took me a while to apprehend it. This was all according to the Spirit's plan for me.
Assurance in a particular believer is no test of salvation. It is a gift given in scripture. Assurance itself is guaranteed in scripture, but any believer's apprehension of it might vary from other believers.