If you mean I as the letter yes it should always be capitalized when stating yourself, but not when it is in *it* or *is* unless it is at the begining of a sentence. But, if you mean I as in me, my self, and I. As in yourself and not the text *I* hmm that is a very weird, but interesting question. Can I be capitalized?..................hmm well if you stand tall then maybe. lol
