I'm kind of scared of my father, and I'm not sure why

I'm kind of scared of my father, and I'm not sure why. When I was a kid, I always dreaded him coming home from work. As an adult, I always avoided being in the house when he was home. I'm married now and have been moved out of the house for four years now, and I still resent my dad. But the thing is, I'm not sure why. I don't have any memories of him being abusive or even particularly mean or anything like that. I just feel really uneasy around him and I don't know why. Does anyone have any ideas of why this could be the case?