Philosoraptor

Because the same thing happens with colors.
I may see an apple is blue, but I'm taught the color of that apple is red, so what I see as blue is "red". You may see that same apple as orange, but you're also taught it is red.

When someone is taught since they're children an ice cream is sweet, even though they feel its spicy, they will understand is sweet. Therefore they will never know it is actually spicy.

but then wouldn't he do the same thing we do when we eat something spicy

No, because if something sweet is understood as 'spicy' for that person, the same thing happens backwards, they can taste something that is actually spicy but they have been taught it is actually sweet, sour or bitter.. That is also probably why there are so many different tastes, like someone doesn't like bitter, or doesnt like ice cream or stuff like that..

k u win smart guy