I keep accurate records of my lifetime win / loss history.
For the past several years it hasn't varied much, it might go down a grand or so, then it will bounce back.
Currently I'm at about the same point I was in 2015, which surprises me.
Prior to that, it was the expected overall losing pattern, slowly worsening, which I expect as I play high limit slots and craps.
I've no explanation for it other than "variance, aka luck."