How long does caffeine in coffee last. Someone told me that day old coffee in my thermal coffee maker had lost its caffeine. Is that true?

Tell that person they need a "CHECK UP FROM THE NECK UP", because that is not true what so ever! If that was the case then how would all of these new cold coffee drinks sold everywhere now, keep their caffiene content after being stored for days or longer.So don't worry, the coffee in your thermos will keep you "POP LOCKIN" all day long.