"I missed a few days and nothing happened"

This looks like an experiment. You forgot the tablet on Tuesday, then Wednesday, then it was the weekend, and by Monday you had a result. Nothing happened. The blood pressure didn't announce itself, the mood held, the chest was fine. If the tablet mattered, surely five days without it would have shown you.

The trouble with the experiment is that it has no readout. For the silent ones there was never going to be a signal, because the condition doesn't produce one, so five silent days are what you'd get from a tablet that was doing everything and from a tablet doing nothing. For the holding ones the effect often outlasts the last dose by days or weeks. An antidepressant doesn't stop working the morning after, and inflamed airways take time to become inflamed. So the five days measured nothing, and the feeling of having tested it is the only result you got.

There's a second problem that I'd want you to know about even though it's less common. Blaschke and colleagues, reviewing decades of electronically recorded dosing, noted that intermittent lapses in taking a medicine are a potential source of harm in their own right, through rebound effects when a drug is stopped and through what they called recurrent first-dose effects when it's restarted. In plain words, for some medicines the off-and-on pattern is worse than either steady taking or a proper stop. That's my summary of their point, and which medicines it applies to is exactly the kind of thing a pharmacist can tell you and a feeling can't.

So what did the missed week show? That you didn't feel anything, which you already knew you wouldn't. What it didn't show is anything about the medicine. If you want an actual result, the cuff, the blood test and the peak flow meter give one, and the person who prescribed the medicine can read it. That's a better experiment, and the next chapter is about the fear that stops people asking for it.