Separate/sort out the men from the boys
Definition 1 of 1
Pro Tip 1/3Real-world Test
Often used when a situation is challenging enough to test a person's abilities or maturity. 
Surviving in the wilderness will separate the men from the boys.
Pro Tip 2/3Experience Highlight
Emphasizes the difference between those who can handle tough situations due to experience or skill. 
In a crisis, you really separate the men from the boys.
Pro Tip 3/3Potential Misuse
The phrase can seem sexist or outdated. It's important to be sensitive to gender inclusivity when using it. 
This phrase is tricky; you don't want to separate the men from the boys in a gender-neutral office environment.