Subjective religious experience

Yet again, someone has tried to convince me of the truth of her religion (in this case, Wicca) on the basis of her subjective religious experience. But since when do subjective religious experiences prove anything? People of many mutually exclusive faiths believe that subjective religious experiences prove their religions. In particular, Mormons trot out that doctrine whenever I'm winning an argument against them on the Bible.

Therefore, if you want to argue that your subjective religious experience proves your faith, you should be prepared to argue either that all of those mutually exclusive faiths are somehow true or that your subjective religious experience counts, while others' experiences don't. You should also be prepared to take into account neurological explanations for religious experiences.