I work in a daycare with kids aged 6 weeks to 4 years. In my experience, kids aged about 20 months to 4 years really think it’s their nose. When talking to an early childhood specialist, we actually talked about this, and she said they most likely believe it because the shape of the thumb between the fingers looks like the tip of noses, and as they are too young to know their own faces very well. Also, because they are met with such a vast variety of shapes, faces, and new information daily, they get used to identifying shapes, and so they can’t distinguish between the curves of the thumb and the tip of the nose as well.

so…. yes. a thumb most definitely looks like a nose. :)

I also remember that creepy thumb dislocation trick my uncle did when i was maybe 5.

Scarred me for life.