I think it doesn't print right messages, if there is only one movement, it should print:
I think that I agree with you. So, the next question is how far apart are the messages, with respect to the motion. Make some changes to the code.
if(currPirState == LOW)
Serial.print("PIR just went LOW at ");
Serial.print("PIR just went HIGH at ");
Let's see whether the PIR switch needs debouncing. I wouldn't think so, but maybe it does.