The country is in famine and nobody knows why. Then the MC comes and tells that the reason for the famine is because they cultivate cash crops instead of food. The princess is extremely shocked, falls to her knees and realizes that the kingdom needs his wisdom and that she would offer him her chastity to bind him to the kingdom.
Another example is with the arrogant dark elf. The MC tells her that the dark elfes should thin out their forest so that the forest stays healthy. She immediatly prostrates before him and gives him her body and chastity.
The only moment I felt that the MC is smart was when he did paperwork offscreen.