I used to find it weird how many people would make an excel formula on data they couldn't intuitively check. Like even basic level 'what percentage increase is a8 from a7' - they enter a formula then don't know if it's correct. I always wrote formulas on numbers I can reason with. If a8 is 120, and a7 is 100 you can immediately tell if you've gone wrong. Then you change for 1,387 and 1,252 and know it's going to be accurate.

People do the same with AI, ask it about something they know little about then assume it is correct, rather than checking their ideas with known values or concepts they might be able to error check.

With or without calculator some people have an aversion to calculation and that's the problem in my opinion. How much bullshit you can refute with back of the envelope calculations is remarkable.

This, and knowing by heart all the simple formulas/rules for area/volume/density and energy measurements.

The classic example being pizza diameter.