What do you call proverbs that use opposing words to sound smart eg To learn, you must forget/ You only lose what you cling to etc it's an example of what type of writing?

Answer 1

The term you're looking for is paradox, from the Greek word paradoxon, which means “contrary to expectations, existing belief, or perceived opinion.” It is a statement that appears to be self-contradictory or silly, but which may include a latent (hidden or concealed) truth.

Answer 2

Paradoxes re a powerful way to make a point, but they often must be developed or expanded to give the meaning a chance to sink in.