I experience this too. I can have a headache and pick up a bottle of advil and take two out and swallow them. And then think did I just take those? Did I only think about doing it? Am I remembering the last time I took them or remembering taking them just now? Pill organizers are the same way for me, I don't trust that I haven't screwed it up in some fashion.

The only meds I don't screw up (as bad) are the ones in bubble packs where I pop the pill out and write the date and time on the package by the empty spot. I still sometimes forget to take those meds.

I used to think my OCD caused me to do things over and over again (it may), but it was explained to me that my inability to tell the difference at times between thinking about doing something, actually doing it, and remembering doing it before become confused when you experience dissociation, derealization, depersonalization. Lack of reality.

I think we realize our med mistakes more often than other kinds of mistakes. I can obsess about whether the vehicle doors are locked and windows are up all I want, but never really be confident that they are in fact up and locked unless I'm standing by the car staring at it (repeatedly pulling on the door handle to make sure it isn't going to open)(hmm, ocd?). As soon as I go in the house then I begin to doubt that they are in fact up and locked. Same concept applies to way too many things including meds.