After taking step1, I was able to remember ~70qs, third of which I KNEW I missed. The score I got suggests that I only missed those 20-something qs I remembered after the test. That's impossible. I"m sure I must have missed at least double that amount of qs.
The point is that there's absolutly zero correlation between how you feel/think you did and your score. Also remember, the test is curved so if your version was exceedingly difficult, and most people did poorly on, then chances are they'll make the curve more forgiving. At the end, it's a standardized exam and they need to produce a bell curve even if that means they throw away half of the qs.