Your brain is still young if you can spot the man in a hat

Your brain combines all these pieces into one larger interpretation.
Pareidolia: Why We See Faces Everywhere

Humans are particularly good at recognizing faces.

This tendency is sometimes associated with pareidolia, the phenomenon in which people perceive familiar patterns—especially faces—in ambiguous shapes.

It’s why people sometimes see faces in:

Clouds
Tree bark
Mountains
Buildings
Shadows
Rocks
Household objects

Our brains are highly sensitive to facial patterns because recognizing faces is socially important.

Optical illusion artists can use this natural tendency to create images that initially look like one thing but reveal