So, I'm a muslim. We have to fast for a month (29-31) days straight yearly. Aftewards, we celebrate Eid (it's the Islamic version of christmas) to celebrate to triumph of fasting for a month. It's necessary for muslims who are sane and above the age of puberty.
Me and my sister have an ability. We can tell the taste food by smelling it. Also, we remember tastes very well so, if we're craving pizza at the moment, our brain will make us think that our saliva taste's like pizza.
So, if I see my sister eating chips while I'm fasting (and I really want some), I'll ask for a chip and smell it. Then, I'll say "Thanks for the chip!"
Odd, isn't it?