I've been having a couple of glasses of red wine lately, in the evenings. I seem to be getting to a sensitive point in my head right now, so I had better lay off for a little while.
Another thing Sacks mentions is that the so-called "trigger foods" don't always cause headaches. Your body has to be at a stage where it is ready to invite one in for those foods to have the effect of kicking in the headache. They do not by themselves cause headaches. I seem to be at that stage, which is why I need to back off.