when a person starts a treatment, and knows of the possible side effects, these effects often seem to manifest themselves onto that person. They could start somethign like minoxidil knowing that it is for hair growth, and begin to see hair sprouting on parts of the body he has never seen before, even though it may have been there for years. This might be because he was looking for it from knowing the side effects of the treatments. if that makes any sense
also, some people may not wash the minoxidil from their hands when they are done applying it, and may touch other parts of their body.