Duality is not about understanding but support according the articles section. Just posting because often I see ppl trying to look for "natural understanding" in duality just to get frustrated.

1. Support.

Ni/Se
Ne/Si
Fi/Te
Fe/Ti

This looks as complementing of one partner’s weak traits by the strong ones of the other. Often people wonder: “What makes them work together, or be friends, they are so different!” However, understanding is not always good in this kind of relations: when one has already understood everything, the other needs to be persuaded, which takes time. More often partners trust each other, because 'he anyway knows and manages it better than me'.

X