Perhaps something of a daft question. I've never found that paracetemol or aspirin has any noticeable effect on headaches or pains and even though I'm still compelled to load up on Strepsils and Lemsip when struck down with the dreaded man flu (in the vain hope that this time they'll help), I can't say my symptoms have ever improved all that much after taking medicine. Most people I know swear by that stuff though.
I think I'm immune to over-the-counter drugs. I'll have to get hold of some heroin to distract me from my sore throat.