Placebo? Situation changing day-to-day? Diet? All kinds of variables. But in this particular scenario, likely placebo. If I tell someone that a tablet will mak

Placebo? Situation changing day-to-day? Diet? All kinds of variables. But in this particular scenario, likely placebo. If I tell someone that a tablet will make them able to do something and it's just a sugar pill, they'll likely be able to do it. The blocking factor is usually a confidence issue.