'Ew'

Ew..it generally means that something is gross, right? I always thought so. I have asked several people what the word 'ew' meant, these are my responses....
Victim#1:....what do you mean? Is this -my name-
Victim#1...-after prompting-: It means degoutant.(it's disgusting..in french)
Victim#2::yucky...nasty....'ew'
Victim#3:disgusting, I guess....
Victim#4:I usually think of ew yuck, ill favored...
There you have it. 'ew' means disgusting, says three people. It's the general consensus that that word means gross, disgusting, horrible looking. And any other synonym I can think of. So, why, I wonder, do most people around me use the word as an exclamation. When one has a good idea, "Ew, I have the best idea! You've got to listen to it. Ew, ohmigod!. Or, "Ew, that car is fantastic! I love it." So, why in the world would you exclaim that something is disgusting, with the expression of 'ew', and then turn around and say it's the best thing in said world? I don't understand it. I am going to search my peers vocabulary, and find other words, that are now being used as their opposites...when they really shouldn't! Well then, what have you to say now? Wait let me guess...."EW!"