why do some choose heaven and some choose hell?

I don’t understand how people say someone “chooses hell.” If two people respond differently to God, there has to be a reason. Either someone was born with a different inner nature, or their entire life, their trauma, their environment, their experiences, shaped them into that response. Those things aren’t chosen. You don’t choose the nervous system you’re born with or the world that formed you. So where does “free choice” actually enter the picture? If two people hear the same song and one feels it and the other doesn’t, there’s always a cause behind that difference. It isn’t random and it isn’t just willpower.