dBASE was not my first language, but learning normalization and modelling completely transformed my user interface design. Starting with dBASE, every UI I built used all available data to do some combination of reducing the potential for error and reducing user effort.

For example, choosing "Tesla" as the make of car should obviously hide "F-150" from the list of models and hide all fuel types except "Battery Only". This seems obvious to pretty much everyone, but there are a lot of UI designs that completely ignore analogous data relations. Less obviously, but just as important, having reduced the list of fuel types to one possibility, it should be automatically filled in.

I find web forms, especially government ones, to be particularly bad at this stuff.