Proverb of the day :- Still waters run deep

Meaning / example :-
People with a quiet manner may often have complex, deep inner-thoughts and understanding. On the other hand, people who talk a lot and brag about how much they know will often be less intelligent or more shallow of thought. Streams where the water is deep don’t make any noise and often appear still on the surface, but in reality a lot of water is being moved beneath the surface. Shallow streams bubble and jump over rocks, making a lot of noise but transport only a small amount of water.