I remember reading somewhere that growing up using imperial makes you take to to math more readily, I grew up as we were switching to metric, all we learnt at school was metric, but outside of school people mostly still used imperial, so I think in a bit of both, if someone says they are 170cm tall it doesn’t mean anything to me till I convert it to feet and inches, but I think in kilometres for driving distance and speed, for measuring where accuracy isn’t important, I go metric, but for accurate measurements like when using my lathe, reloading etc I go imperial, can’t imagine reloading in grams, I’ve bought a mil/mil scope a while ago and have been trying to teach myself to think in mil, but I keep finding myself converting mil to MOA which is sort of annoying.