What Makes Something Spiritual or Not-Spiritual?

What do some actually mean when they say, “I’m spiritual but not religious?”or “I’m not spiritual?” And what do others mean when they say,”I identify as a mystic?” Can humanists also be “spiritual?” Are these descriptions mutually exclusive?  Could it be that labels we may or may not use misrepresent our own experiences? In the early 1900s, the “father of psychology”, WilliamJames, broadened the understandings of religious experiences in his classic work, The Varieties of Religious Experience. Contemporary neurological research may also be expanding our knowledge of our human experiences, including what we may call “spiritual experiences.”