We don't have to use idioms to express ourselves,

but we do need to know what they mean so we can undertand them when other people use them. I seldom use idioms in my daily conversations or correspondences. 

Here are a few my husband taught me a long time ago when we're still dating:

in a New York Minute: a very brief span of time : instant

He'll fix any little thing that's wrong in a New York Minute

That kite got too much tails: showy, too much details

The Platte River Syndrome: Platte River is very Shallow, but wide

That guy got the Platte River Syndrome, 6-inch deep, one-mile wide. This means that guy talks a lot without much substance.:)