...ok, so flipping the y-axis.
I reckon that I do it because my first 3D game was Microsoft Flight Simulator (I haven’t looked this up but I’m pretty sure up and down are flipped in that game by default, like a real plane).
My brothers, meanwhile, who are all younger than me and had their first 3D experience on PS2/etc all prefer standard y-axis.
So what got you into flipped y-axis, if you use it? Something in real life that you were used to before getting into video games? One specific game that locked you into it?
I haven't. Unless it's forced on me (like Final Fantasy 12's reversed/inverted controls for the camera) I try to avoid it. It just doesn't feel "natural" to be pulling down to command the camera to pull down only for the camera to move UP.