I made the mistake of pushing the "Trigger Reputation Recalc" button on this page http://stackoverflow.com/reputation. Which triggers this url stackoverflow.com/reputation?recalc=true.
After this my rep went down from 4,624 to 4,205!!! Why did this happen? I know a few years ago there was a big automatic rep re-calc and I lost over 1000 rep then, has my rep been inflated this whole time or is it a bug!
It would be nice if there was a big disclaimer on that button "Warning this might cause you to lose reputation!!!!"