🧑‍🤝‍🧑 / 🏡 What is a sign that someone is much smarter than they let on?

[TerryP]

I always watch the quiet ones when things are going awry.

 

[cj6891]

Silence.

 

[footballer]

When a person tells all they know, they are really telling what they don't know.

Quiet people would rather listen to other people and learn rather than hear themselves talk.