Congratulations on your good luck. You cannot systematically beat a CSM.
As for what you observed, see:
http://en.wikipedia.org/wiki/Confirmation_bias
http://en.wikipedia.org/wiki/Availability_heuristic
Edit to add: what was your system for bet size management? It is easy, with bet size manipulation, to create a situation where you'll have small losses at most table sessions and large wins at a few. The house edge is unchanged and you will still lose over the long term.