What's the difference between these sentences in their meaning? Maybe, "will" is used here as modal verb 'to say that someone is willing to do something. You use will not or won't to indicate that someone refuses to do something.'. But I can't understand the real difference between these sentences. Could you explain it, please? Feel free to provide some examples to explain the good of using "will" here.
Keep in touch. I want to know how you are doing.
Keep in touch. I will want to know how you are doing. (Is "will" willing to know here?)