Sometimes it's literally just semantics. The individualist sections of leftism seem to believe that nobody has more power over their body than they do. That no ruler or god can overrule their own judgment on how they treat themselves.

I personally subscribe to this philosophy, but I would never go as far to say that I am god. I am me and God is God. God is free to give me guidance or advice, even make demands, but my decisions are ultimately mine and the consequences are ultimately mine.