What makes a person corny?

Corny men and women, how can you tell when it's not obvious.
If it was obvious I wouldn't be asking this question but some people can be obvious cornballs.
Some people gets called corny but they don't even try to act cool, they are just acting themselves so in this case they are being called 'cool' instead of 'corny' because double negative.

Defintion
Corny - A lame person that acts cool.

Key points to answer in your excerpt (if you are a girl, talk about corny guys and if you are a guy talk about corny girls)
What are their actions?
How do they act cool?
How do they dress?
What are they like in relationships?
How can you distinguish a corny person from a normal person?
Updates
+1 y
I love open discussions. It's to educate everyone and see other people's opinions and views. In the future people that looks up this question on google out of pure curiosity can know.
What makes a person corny?
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