I Am Obviously a Genius, but the Empress Forces Me to Eat Soft Food!

He is obviously a genius, so it should have nothing to do with my protagonist, right? The genius of the past generation became useless due to a serious illness. However, the good-for-nothing was spotted by the empress. Protagonist: I am a genius, I want to conquer the world, I want to become famous! Cold Empress: ... Don't run around, finish the soft food first. Slowly, with the help of an unreliable old man, the protagonist grows rapidly, and the empress gradually reveals the reason for marrying him...