When you use a negation, the meaning of the sentence is reversed.

He tends to view things from a pessimistic perspective.

Our feelings of mourning for his death are deep.

He was mourning his deceased grandfather.

Her sobbing echoed throughout the room.

She sobbed quietly, lost in sadness.

Every morning, Gu spreads boiled butter on his bread and eats it.

My grandchildren are the joy of my life.

This is my favorite cafe.

I wonder what this guy is thinking.