"I Want" Indicates "I Can't"

People want things that will make them feel good. We want food and sleep and companionship and all those things that make life bearable (if not downright survivable). When we find ourselves somehow unhappy, we want whatever it is that will satisfy us, and then we go and get it. 

If I'm feeling lonely and I want companionship, I call my friends and converse with them. There's no reason to announce that I want to talk with them; I just do it. 

The only time people say "I want" is when they can't get it. If I say "I want to talk with my friends", that indicates that for some reason I can't. It could be for any number of reasons, such as not having a working phone or being occupied by other obligations, or from imagined hangups like thinking that those friends are busy. Regardless of whether or not others find the reason valid, in the speaker's mind, it is not possible.