Could someone help me understand this pisces guy?

There is this pisces man that I like (i am a virgo) and sometimes he will be so sweet and caring and other times he will be quite and ignore me. He plays it off as though he isn't even aware and is aloof to his surroundings and me. I was just wondering if it is typical of a Pisces to have these emotional swings and if it is, what does it mean?